People call her “quirky,” but that doesn't begin to explain my daughter. Gaining a diagnosis seems like a step forward, but will it change her future?

At the age of 9, on the brink of fourth grade, Paisley still grabs my hand and holds it when we walk side by side. I know that other kids her age no longer do this and that if we are spotted, it's likely to be one more thing that makes her different. But she is my youngest, the last small hand I will hold for a long, long time, and I can't bring myself to drop it and make her walk on her own.

She has a round head and hazel eyes and deep dimples in her cheeks. I keep her hair cut in a chin-length bob, a spunky look that suits her personality. Despite the fact that I point a camera at her regularly, rarely does a photo capture her most attractive features. When told to smile, she bares her teeth in what could best be described as a grimace.

If it were obvious, I would have known sooner. But it isn't. Paisley doesn't speak in a monotone. She doesn't disassemble the DVD player to examine the parts. She doesn't memorize the television schedule or insist upon the exact same routine every day. She looks me in the eye. If you, like me, were to pull up the lists of symptoms and indicators on your phone for autism, Asperger's and other scary words that somehow seem alien and distant late in the evening when the kids are in bed and you should go to bed, too, but can't because you're wondering again just what might be going on in your child's head, you'll find that you answer “no” to the first three or four things on the list. About half of them don't apply at all. But that other half. The other half keeps you scrolling in the dark.

Paisley is bornwith her own agenda and a chip on her shoulder. She's fussy, and she sleeps and eats when she wants to and not a moment before. I try all my best parenting to soothe her. The rest of the family gets used to the sound of a cranky baby in the background of our lives. Whining mixes withDora the Exploreron television in the living room for my other daughter and the shouts of my son playing video games in the playroom.

Once Paisley learns to talk, she can translate her dissatisfaction into words. I tell her it's time to take a bath, and without looking up from the My Little Pony she's walking along the bottom bookshelf, she gives me a matter-of-fact, “No.”

I try cajoling, then being stern, but she digs in her heels. She yells and holds out beyond all reasonableness until we're in a battle. The instigating incident isn't always a bath. It might be a request to set her crayons aside while we have dinner, or to pick up her books or to drink her milk. As her vocabulary grows, so does her ability to stand her ground. “You're the worst mom ever and I hate you!” There's a teenager's anger in my toddler's mind.

I try to explain her, my scowling girl in the sundress and snub-nosed sandals: strong-willed, stubborn, opinionated. Those don't quite do her justice, so I add superlatives: the stubbornest child ever, the most strong-willed person I've met. I can't make anyone understand with this handful of inadequate words. The pediatrician, Sunday school leaders, the preschool teachers all nod at me, and I can see behind their feigned understanding a measure of blame. Permissive parent, they think. She needs structure and consistency and rules. That's not me, I want to insist. It really isn't. The frustration over being misunderstood is nearly as great as the frustration over her behavior.

Sometimes I think she will grow up to be someone phenomenal, and this will be my reward. She will rule her corner of the world, whatever that may be, and accomplish something beyond my dreams.

At moments, she's perfectly sweet. She wraps her dimpled arms around my neck and hugs me. She loves books and will cuddle for long, luxurious periods of time while I read to her. She plays with her pretend kitchen, cooking up plastic meals to feed to us. My adult friends love her truthfulness and blunt delivery. When asked, “Paisley, do you like chocolate?” she answers, “No,” and goes back to the picture she's coloring without elaborating. She'll be a strong woman, they say. We are in our 40s, and it has taken us decades to learn the value of our opinions and making sure they're heard.

But by the time Paisley's in kindergarten, there's a consensus: Something isn't right. Whatever it is has a host of nebulous symptoms—in addition to being argumentative and obstinate, she's clumsy, often bumping into door frames, falling off her little chair during class; her gross motor skills aren't as developed as they should be. She's smart, though, and I clutch onto that. She reads well above the benchmark level for her grade. She remembers certain books we've read years after we've returned them to the library, and she delivers cleverly funny lines, deadpan, with perfect timing.

We begin tests and evaluations at the school and through Nationwide Children's Hospital: a vision exam, a physical therapy evaluation, assessments for speech therapy, occupational therapy, adapted physical education, attention deficit disorder. I learn how a parent's life might be consumed by a child's medical condition. Because my profession is parenting, I am the one who handles communications, who makes the calls and takes her to the appointments. I report to my husband in the evening.

The results are all the same—just barely in the normal range. If there is a line that demarcates normal in any of a dozen aspects, Paisley exists in a constant state of hovering just above it, sometimes unaware of a dangling toe that has dipped just below.

With no conclusive answers, we all agree to “keep an eye on things.” Which means only that we've run out of ideas. I tell myself I've done everything I can do as a parent, and that gives me some measure of peace.

By second grade, her differences are becoming more pronounced. We have a meeting at the school—specialists, teachers and me. Again, we agree that something is off. We talk about what we've tried and the issues that we can't seem to resolve. She's getting older, and some concerns that might have been attributed to normal young-child behavior have not resolved. She takes longer than the other kids to finish a worksheet or pack up her backpack. She still has outbursts of anger. She hums to herself; she talks a lot about the very detailed “Imagination World” she's invented in her mind. She's weird in a way I find loveable and marvelous.

No one has ever suggested to me that Paisley be evaluated for autism spectrum disorder. But when I say I think maybe it's time, no one tells me I'm crazy.

The evaluation consists of a number of sessions with a psychiatrist: intelligence tests as well as other assessments and sometimes just conversation. She calls me to her office when she's completed her report. “This is the full report,” she says, “but what you probably want to know is that I have diagnosed Paisley with Asperger's syndrome.”

I nod, very aware of my face and my body language and trying to keep both placid.

“How do you feel about that?” she asks.

I think for a moment, wanting to be truthful. “Relieved,” I say, finally. And this is true. Because it wasn't all in my mind. Because the struggles with Paisley weren't because I was a bad mother. Because now there's a word to explain why she is the way she is.

Soon, though, the diagnosis makes me sad. Days later, I look at my little girl, her face impassive as she works on a drawing. She bends her head over her picture, and I think of peonies with lush blooms, heavy and full, weighing down their slender stems. I want for her what every parent wants for their child—a happy, productive life. How hard will that be for her?

There are as many strategies for living with autism spectrum disorder as there are children who exist there. I don't know what the best path is for us. She can pass for typical, and often, I let her. But now that we have a diagnosis, the word—Asperger's—is mine, and I can use it when I need to. Most people have at least some knowledge. They think of television characters—the super-intelligent, awkward professor, the odd girl who marches to the beat of her own drum. The nerdy hero. Today, she doesn't use it as a word to identify herself. But maybe someday she will.

I worry. I crack the seals on her water bottles before I put them in her lunchbox because she lacks the coordinated strength to do it herself, and I think about middle school, when she will need to find all her classes and work a locker and change clothes for gym class. When the kids might be mean. I work to help her manage her anger and make friends. I work to enjoy the fascinating and wonderful things about the way her mind works and let the irritations slide by. I hope that someday, she will find her place on her own. But for today, I will hold her hand.