I think about "passing" a lot when I walk on the beach.

I'm a white woman with graying but formerly dark hair and olive skin. I tan easily. I'm mother to four, three I gave birth to and one I adopted. That last one, the adopted girl, is biracial -- Caucasian and Jamaican -- with a cascade of dark brown hair to her waist and shiny onyx eyes. She looks remarkably like me. Her next-older brother has blond hair trailing down his back and blue eyes (go figure). We just spent a week in Florida together, the two kids, me and my mother. All week long, people assumed I'd given birth to the girl and that the long-haired boy was a girl.

Half the time, I corrected people. The other half, I just left others' assumptions alone.

* * * * *

I didn't want to deny anyone -- including my children -- the truth. At the same time, it's cumbersome to point out that your swimming trunk-clad boy is a boy despite his long hair and that your daughter might "look just like you" yet not be biologically tied to you.

If my kids know they are who they are -- bright, sweet, scrappy girl and smart, athletic, long-haired boy -- does it matter whether strangers know anything beyond their first impressions? When people call my son my daughter, we generally roll our eyes at one another and shrug. My daughter is secure in my being her mama; at this point, at least, no further explanation is necessary (that could change or it could remain true, I don't yet know). She is starting to grasp the tummy mommy notion -- that she started off in another belly and very quickly landed in my arms. At 3, that's plenty. We try to walk a fine line of not hiding and not pushing the information upon her.

Casually chatting with strangers, though, I think about these things. Last week, I was sharing birth stories with the mother of a little girl by the swimming pool. I had three stories, not four (although I was at my daughter's birth and could have said, "Caroline needed only three pushes, too").

On that Florida beach, where hardly any black people are sunbathing and romping, I think about what it might have been like had we adopted a very dark-skinned baby, as we'd imagined we would, one whose adoption would have consistently been the first thing people noticed about the child. Race would have been at the forefront of our minds much more, and we'd need a two-sentence explanation for kids who wondered aloud why she had dark skin and we didn't.

* * * * *

My daughter is not alone in being biracial. Last week, The New York Times reported new census data: "Among American children, the multiracial population has increased almost 50 percent, to 4.2 million, since 2000, making it the fastest growing youth group in the country. The number of people of all ages who identified themselves as both white and black soared by 134 percent since 2000 to 1.8 million people." This data only affirms how student groups across the country are organizing not only by single race but instead as multiracial and biracial. (The New York Times story looked at this, quoting 19-year-old Laura Wood: "If someone tries to call me black I say, 'Yes -- and white.' People have the right not to acknowledge everything, but don't do it because society tells you that you can't.") At my daughter's preschool, amongst her small cohort are three other biracial or multiracial children (along with a Vietnamese boy with two blond sisters, adopted by a white lesbian, half-Jewish, very blond couple).

On home turf, neither being adopted nor being biracial are unique to her; even on our block, there are two other girls who were adopted (both with older brothers born to their mothers). In the context of daily life, I can trust that openness will prevail. She and I went to her next-biggest brother's kindergarten class once her adoption was finalized to share the news with his peers, including a boy who'd recently been adopted by his aunt.

Home turf seems an easier place to hold firm to our identities in comparison to beaches and strangers. In that same kindergarten, one of my sons' classmates came up to me every morning for two months to tell me my son looked like a girl. Every morning, I answered, "He has long hair, but you know he's a boy, right?" He'd nod that he did. They liked each other tremendously. The exchange with me -- for whatever reason -- mattered to him, and so we affirmed -- and reaffirmed -- that boys can have long hair and still be boys.

* * * * *

Then, at the airport, my daughter wandered up to a baby in her stroller who was being fed baby food from a jar. The baby had Down Syndrome, and I saw my just-turned-3-year-old daughter register that this baby's face was different from other babies' faces. We said hello and talked about baby food for a moment and moved on. I saw in the mother's eyes a flicker of recognition that my daughter had noticed something. I saw her steeling herself to respond and then looking very relieved when that line of conversation didn't take place and we continued on our way.

Being matter-of-fact about our realities -- a boy with long hair, a girl with two sets of parents, a child with special needs -- means, ultimately, that all these things aren't such a big deal, right? I am comfortable with my two-sentence explanations, pretty breezy with them. Openness helps us move beyond the two sentences provided up front to the reality that each of us is more than the first "different" thing about us.