I have mentioned it before, but it happens often enough to mention again.
My 4 yr old was going thru the list again:
'the baby was in your belly?'
'Cody was in your belly?'
'i was in your belly?'
'no, you were in your other mom's belly'
'Lizzy was in your belly?'
'no, she was in someone else's belly too'
*eyes light up with interest*
'whose belly was she in?'
'a lady name S***'
This is exactly why I wanted to have more than one adopted child. I never wanted Lizzy to be the only one who 'wasn't in my belly'. She has no concept of this yet, but I could tell that it made one of my newest daughter feel better about this. Then, having grown up in foster care, she immediately said 'she's staying here, forever, like us?'
'Yes. She is staying here forever, just like you are.'