The average life expectancy for women in the U.S. is anywhere from 73.5 to 86 years of age. As the 49-year-old mother of a four-year-old, if I kick when I am 73.5, I’m going to be pissed.

That said, I always knew I’d be an older mom. When my college friends were getting pregnant in their twenties and thirties, I never felt I was missing out. It was only after marrying Tony that I can truly say I caught “baby fever,” and by then I was 40.

“Perfect,” I thought. I knew plenty of 40-something women who successfully got pregnant with their 40-something eggs and gave birth to perfectly healthy babies. I would, too. Why not? I didn’t look my age. If someone asked, “How old are you?” I’d say without flinching, “I’m 40,” and was always secretly thrilled by their reaction: “I thought you were 30!” Oh stop now…. If my outsides look 10-years younger than my biological age, I reasoned, shouldn’t my insides look just as good?

Apparently, this is not how it works. Needless to say, I now know plenty of 40-somethings with tired old eggs, me and my eggs included.

I was 44 when I looked to domestic adoption as my means to motherhood. The month before our daughter’s biological mother gave birth and relinquished her parental rights, I celebrated another birthday. And at 45, I had a beautiful, healthy baby girl to love and look after.

It’s only within the last year that I’ve begun feeling anxious about my age. Maybe it’s because the newborn/toddler stage, wrought with sleep deprivation and newfound new-mom worries, was such a blur. I constantly felt my brain stutter through every thought, I’d wind up saying things like, “She sick. Me crying.” I’m still amazed I had that much clarity.

But now that Beth is four, it’s seems I can clearly, if somewhat obsessively, contemplate my demise. Yes, it’s all well and fine to look younger than my calendar years, but when I think about my age, the actual number—49—and the mortality stats, it’s shocking to consider the possibility that I could have only 20- or 30-something years left on this earth.

Shocking and quite unacceptable actually, since this means I might not be around to see my 20- or 30-something-year-old daughter’s career take off. Or help her plan her wedding, or see her through childbirth or the adoption process, or be a lunch date away from hearing about all the joys and sorrows that life will undoubtedly send her way.

But here’s what’s truly upsetting about being average when it comes to dying – I wouldn’t be around to see the day my daughter sees her mother, and her biological mother, through a grown-up lens.

What will it be like for her to fully grasp that we were human, just like her? That we were each figuring out our lives, each enduring our own disappointments, missteps, and blunders along the way? I hope she’ll look at us with understanding, kindness, and an empathetic eye roll, knowing in her heart that in spite of our inadequacies, and how crazy we drove her, we loved her. So very much and did our best by her. Who knows, maybe she’ll discover that we were even right about a few things? Imagine that.

Well, I, for one, don’t want to miss it. So, other than trusting that genetics are on my side, and watching out for the errant bus as I cross the street, I have decided that “average” isn’t going to cut it.

I recently met with a nutritionist and have started eating a low-glycemic diet. I am now “jawking” or jog/walking, for 30-minutes, three times a week. Sure, it’s always nice to have a clear separation of thigh and butt, but these days my focus is on doing everything that’s in my control to have a healthy strong body and an energetic life – no matter how long it might be. (Sigh….)

However, I’m shooting for 100. Who’s with me?

This piece was originally published in Adoptive Families magazine.