An interesting development has occurred here in the last week: the girls have discovered baby dolls.
Nana and Pop gave them a set of "newborn twins" baby dolls for Christmas. I was somewhat skeptical they'd get the idea, and initially, they showed no interest at all. However, all of a sudden, the baby dolls became favored toys. Katherine has just spent the last hour bringing me her "bah-bah" and its hat. I have to put the hat on the baby, and pantomime feeding and burping and rocking the baby, and then she wants to take it back to do the same. Claire, meanwhile, tries to feed the baby a sippy cup of milk. Both of them love to hold it and kiss its head.
I find it fascinating that they recognize it as a baby, and that they try to feed it and love it. It really seems to be innate -- I didn't show them how to play with the baby doll, or encourage any interest in it.
One odd thing: when I pretend to feed the baby, I put it to my breast. After all, that's how I fed Claire and Katherine, and will hopefully feed any future babies. I'm a big proponent of breastfeeding, and will strongly encourage them to nurse when they grow up and have babies of their own. So why does it weird me out to fake-nurse a baby doll?