Willow re-enacting the Normandy invasion in the back yard.

While I wasn't looking, my daughter became a friggin' genius. At least, that's how it seems to me. Everything comes so easily to her: words, numbers, letters, imaginative play. I'm so used to the feeling of working so hard to help Billy accomplish those normal milestones that when Willow does something completely normal it seems like magic. Like a miracle.

She's known her alphabet for months now. You know, the little ABC song. But then about a month ago, she started to show us that she knew letters out of context as well. And she knows most of their sounds. When she's in a really good mood, she can count to sixteen (I don't know why sixteen; maybe she's already counting the years till she can drive), sing six or so songs, name every member of our family, half a dozen colors and use a few short phrases: “He sweet.” “I hold this.” “Read it.” “No more letters.” And “Wucky. It stinks.” That last one was her review of broccoli.

She even happily asks to brush her teeth with her Hello Kitty toothbrush: "Teeth! Teeth! I hold Tooth Cat." (Hello Kitty is now and forever always "Tooth Cat" in our house.)

Did I mention she's nineteen months old?!

I know I sound like I'm bragging – and I am a little – but her precociousness kind of terrifies me. It's like she has Billy's memory but without showing any of the autism traits. At least, not yet.

And I know that makes me sound crazy. But I can't help it. I scrutinize every little behavior to try and see any signs of ASD. Is she shaking her whole body in some stimming behavior? Oh wait, no, she's “wiggling” because the Little Einsteins are telling her to wiggle. Did I mention she's also really good at following directions?

Occasionally, I'll get worried that I'm not giving her enough undivided attention. Even though she's home with me during the day, I spend a great deal of that time dealing with Billy's therapy appointments, planning after-school learning projects for Billy, emailing Billy's teacher, writing about Billy ... meanwhile, she's over in the corner teaching herself French and playing some elaborate game like “United Nations Economic Summit” with her dolls and nobody's noticing.

Any day, I'm expecting her to come up to me and say, “I've finished your taxes and paid the bills. If I program some new widgets into your website will you sit down and blow me some bubbles?”

Even her birth and the months right after are a blur to me. Long after I finished off the bottle of Vicodin that came with the C-section I was walking around in a bit of a fog.

That was the same time we were getting Billy's official autism diagnosis, and though I didn't realize it at the time and though I was deliriously in love with my baby girl, I couldn't allow myself to get lost in the joy of our new little person.

The upside is that she's been there right alongside me throughout Billy's therapy, and she has definitely benefited. She sings songs from the early days of Music Therapy that she hasn't heard since before she could talk.

And I've become a better communicator because of Billy's therapy – better able to encourage communication in both my children. I wish all parents could have a good speech therapist, occupational therapist and behavior therapist on staff, because there are so many wonderful things to learn that really can make a difference in everything from talking to tantrums.

Try as I might to turn blogging into a learning activity for her, she's not buying it. And I'm starting to get more and more freelance work – the money of which we can really use – so she spends more and more time playing at my feet. In fact, the other day I found her beating my keyboard with one of her dolls and saying, “Working! Working! Working!” Either the doll was supposed to be me typing -- or Willow is starting her own blog about what an a-hole of mother she has.

All of this is the long way of getting around to a big admission: We're going to put Willow in preschool. I will miss her like air, but I know she's going to love it. She needs friends – besides this big, old one who can only blow bubbles so long before needing an oxygen mask. She needs structure. And she deserves to have a day centered around the sorts of things she enjoys: music, dance, art, and lots of learning.

She's going to a great preschool. In fact, it is such an adorable, joyful place that I always feel like I've walked into Santa's workshop when I go in there. That is, if Santa relocated to Florida (which, let's face it, he ought to do). I wish they'd let me enroll.

We haven't set Willow's official start date yet, but it's coming soon. I haven't had an empty house during the day in over four years, and the thought kind of terrifies me. Would love to hear thoughts from those of you who've pushed your last little birdie out of the nest (at least during the daytime). Did you feel guilty? How much did you worry? How did you handle it?

Meanwhile, I'm going to assuage my guilt by joining Willow, Paddington Bear and The Little Einsteins in a game of Parliamentary Procedure.