I think Meg thinks stretch marks = baby currently in belly. Which I suppose is pretty much what I taught her. When I was pregnant, she’d point to them and say “you have owie?” I’d say something like “no, they’re not owies, it’s just because Baby Paul is in there.” So the other day, after I got out of the shower, she ran up to me and said “Mommy! Baby Paul in your belly!” I said “No, he’s right there” and pointed. “Remember, he came out of mommy’s belly?” She stared at me, then said “um, OK” in a voice that implied suuuuure, mommy. Whatever.
I can’t tell if she doesn’t get it or just has trouble with tenses – like if she meant “Baby Paul WAS in your belly” and doesn’t understand what “he’s right there” has to do with anything. Right after he was born, she was pretty clear on the ‘this is the baby that used to be in mommy’s belly, then came out’ story. I think she just forgot and since she rarely sees stretch marks, her brain defaulted back to what she was told for months: those marks are there because Baby Paul is in the belly. Right now.