So, yesterday evening, as we were coming back from dinner with my father-in-law, G piped up from the back seat:
"Hey, Mom, could we get an adopted brother or sister for me?"
I nearly ran off the road, but I caught myself, kept driving, and said, "An adopted brother or sister, huh?"
"Yes," she said, "and it would be good if they were my age."
"We only have two bedrooms, though," I said. "If there were another kid in our family, you'd have to share your room with him or her."
"That's OK, I don't mind," she said. "Do you think we ought to get a boy or a girl?"
"I don't know," I said, playing along. "I think if it were a girl, you'd fight over clothes, but if it were a boy, you'd probably tease each other a lot."
"Maybe a girl then," she said.
She's always said she loves being an only child, so I'm not sure where that came from. When I asked her later to explain exactly why she wanted a sibling (after I told her that I wasn't going to adopt one), she said, "Well, I already have two pets, so all I need now is a brother or sister." I pointed out that a brother or sister was not the same as a cat or a dog, and she said "Yes, I know."
I'm guessing that this is a passing fantasy about having a built-in buddy for the weekends rather than a sign of some deep psychological need, so I should probably just try to start setting up more play dates for her. Although with school, her afterschool program, and Girl Scouts, you would think she'd be getting her fill of other kids. Hmmm.