My daughter recently turned 13.

"Does she know what it means to be a teenager?" someone asked.

"I think so — but I'm not really sure," I said.

Erin, who has an autistic spectrum disorder, knows that 13 is not 12 — nor is it 14. Whether she understands that 13 is "greater than" or "less than" either is unclear to me. She is not good with numbers. I've never been much of a numbers person either, though I have come to understand that some numbers hit harder than others

When you have a developmentally disabled child, a part of you does not want them to grow up. Watching their body outgrow their mind and ability to reason brings with it a terror all its own. You want to push the pause button — or better yet, hit rewind.

When they are small, a lot of behaviors can be passed off as simply part of the terrain of being just what they are — small. The meltdowns and sudden swings of emotions in any variety of public spaces can easily be passed off as "normal" when they are young enough to be picked up and whisked away, out of ear and eyeshot. But now, Erin is stronger than I am. She can no longer be quickly removed in what we had perfected as our ongoing series of "nothing to see here" moves.

These days, when things are not going our way there is a lot — and a lot of her — to see. We attempt reasoning, bribing, threatening (we will not go to the library) to get her out of certain situations. Sometimes when we are in a store, she will spot, swipe, or hold with a vice-like grip any number of small random objects — be it a rubber yellow duck, a stuffed Elmo, or a King Kone ice cream. Contrary to most behavior therapists' advice, generally we just buy the coveted item and move along, thereby averting a public tantrum. At home, we have a mountain of random junk we have purchased to literally "buy" our way out of sticky situations. Maybe we should care less about what the person on line behind us thinks — but we are human, as are Erin's three younger brothers. Sometimes, if the only path to momentary peace in all forms is an 18th copy of Clifford the Big Red Dog, you just go with it.

As the years pass and Erin more closely resembles the physical adult she will one day be, it's been difficult not to imagine what the future may hold — where will she live, who will care for her, who will love her. Shortly after we learned of Erin's condition, I asked a doctor what we could do to help her. In addition to a variety of therapies, he said: "I would suggest you have more children — so there is someone to take care of her — when you are gone."

My husband and I were not in the same place when we got the diagnosis. He had returned to New York, where he was starting a new job, when the geneticist called him to discuss the results. Bill, as stoic as they come, walked to a small park on First Avenue, sat on a bench, and cried — crushed under the weight of a dramatically altered future for his daughter, and the prospect of calling to inform his wife of this swift and sudden change of course.

Though deep down we had a feeling something was "not right" as Erin began to fall behind the first year's milestones, we were both still living with the "outside range of normal" assessment a neurologist had offered a few months earlier. With a child of 22 months, with any child, I have come to learn, you're often just shooting for normal: walking, talking, school, sports, friends — or what, at the time, you figure is the natural progression. Up until that point, we had a hazy image of what the future would hold. It was pretty typical, and typical looked pretty good.

In the months and years to come we combed the city looking for direction. I remember remarking to one highly respected neurologist that I thought it strange he had not seen any patients with this disorder before. "Well most people here (as if I were from another planet) do prenatal screenings and terminate should anything appear abnormal." I had no response.

There's a reason there are such high rates of divorce in the special needs community: A disabled child takes a formidable toll on a marriage — physically, emotionally, financially. Bill and I are fortunate to have an exceptional network of friends and family to fall back on, and still it is not easy. Now, it's not as dire as it could be, and we are blessed in many ways: Erin is physically active and engaged in the world around her and genuinely enjoys her life and the people in it. But her diagnosis terminated many of the unspoken hopes we had for our daughter — and how a couple processes that and confronts the unique behavioral, medical, and psychological challenges that it entails is something no support system, however wide or deep, can ever really answer.

For much of Erin's first two years, my father-in-law, a high achieving, big-hearted businessman who tried hard to understand the extent of her disability would consistently ask: "What I'd like to know is will she one day be able to walk down the street and buy herself a cup of coffee?" I never really had an answer to his question. But it is unlikely.

With all the uncertainty that Erin's and our future holds, what I do know is that as she has grown so has her exuberance for the most seemingly mundane particulars of life. Little kids jump up and down all the time at the thought of an ice cream or a toy store. So does Erin. She is five foot five inches tall, and 140 pounds, and still she jumps and claps in delight at the sight of her favorite places or people: "Look Mom, a book store! I am so happy!" Or: "Here is grandma," she shouts — and bounds into her arms.

Erin is a joyful soul. Though her body has begun to change and puberty is upon us, she is very much a child and not saddled with teenage angst or attitude. She does not use sarcasm — figurative language alone perplexes and amazes. "Is your head going to blow up, Eileen?" she echoes, after I have overreacted to some situation generally involving her three younger brothers. "No, Erin, it's not really going to blow up, that just means I am frustrated."

As the unanswerable questions have piled up over the years, what I do know today is that I have a teenager who shares my passion for books and music. Who loves ice cream and chocolate chip cookies, pancakes, bananas, and blueberries. Who waxes poetic at "the dancing trees" blowing in the wind, yet does not know that 45 is older than 37. Who is more affectionate and effusive than I — and most people I know. Who loves and hugs unconditionally and brings smiles to all who cross her path. Erin lives in the moment and the moments with her are good. There's something to be said for that.

I am lucky. I am grateful.

And whether she knows what it is to be a teenager, she knows what it is to be happy — and she knows what makes her smile. Not a lot of teenagers — not a lot of people — do. For Erin it's very simple. Her nursery rhyme books, her service dog, her friends and family gathered around to sing and help blow out the candles — all 13.