Mother, candy, and the psyche

IF my adopted girls go to Chinese class, they get candy. Any kind. Bribery is not a noble parenting tool, but I'm here to say it's efficient, convenient and practical. Any guilt I feel fades away when we come out of class and they're singing those Chinese songs, drilling each other on the Mandarin words for moon, star and underpants. They love it.
  Someday, they'll thank me. I'll be a hero. They'll say, "Thanks, Mum, for making us learn Chinese," when they're all grown up and visiting the orphanages that once housed them.
  Now, we're in the car on the way to class, and they're trying to decide which candy they'll choose. We pass Sunshine Kids, the place where Anna, 7, went to preschool. "That was my first school!" she announces to her younger sister, Sasha.
  "I know," Sasha answers. "You tell me this every week."
  She does. Today she goes further, and begins naming every teacher she's ever had, and then every babysitter she's ever had. Soon Anna has taken out a pen and a notebook, and is doing the tally.
  "So that means I had seven teachers," she says, "seven babysitters and two mums." Two mums? Well, now wait a second. Where did that come from? And she's just talking about this so ... casually?
  "Two mums?" I ask.
  "You and the one whose belly I came out of," she says.
  Well, glory be. We've had so many frank discussions over so many years about what it means to be adopted, and it has never, before now, seemed to have even entered their minds. Whenever I come to the subject, my children appear bored with it. So I don't push. I go for the factual, simple declarative: Some kids are raised by their birth mothers, some by birth fathers, some by adoptive parents and so on. And my kids practically yawn at me. This is the first time either has brought it up on her own.
  "So, do you girls remember your birth mothers?" I ask, gently prodding. If the records are correct, neither would have spent more than about a day with the woman who gave birth to her. Anna was found on the steps outside a hospital. Sasha was found in a cardboard box by a pharmacy.
  "I don't remember her," Anna says, "But I think she had long hair. Probably longer than Sasha's had."
  "Mine had short hair," Sasha says, wisely surrendering.
  "Do you think they were nice?" I ask.
  "I think mine like to sing," Anna says.
  "Yeah, mine, too!" Sasha says.
  "Well, I never got to meet them," I say. "But I met some of the women in the orphanages who took care of you, and they were all nice."
  "That's right," Anna says. "How many of them did I have?"
  "I don't know," I tell her. "I mean, there were a lot of people there."
  "I'm just gonna say six," she says, and then takes a moment to come up with her grand total. "Twenty-two. I've had 22 ladies watching over me. Wow. That's a lot of love for one kid," she says, mimicking the way I talk to her about such things.
  "Snickers," Sasha says, out of nowhere. "I forgot about Snickers bars. I think that's what I'm going to pick today for my candy."
  Right. I forgot, too. Teachers, birth mothers, candy, all part of a well-balanced psyche.