Where do babies come from ?

Khushi : Mumma , Ma'am told (yeah she already goes to school and is in Jr KG) that babies come from mumma's tummy.
Me : Yes (Already thinking whats ahead)
Khushi : I want to go in your tummy !! (trying to pull up my kurta)
Me : Noooo !! (frantically trying to keep my clothes in place)  you cannot , once babies come out , they cannot go back.
Khushi : How did I come out ?
Me : Doctor took you out , they have special scissors to do that
Aryan : Khushi , you know I was also in Mumma's tummy
Khushi : Haan I know , you were pushing me all the time !!
Me : Huh !!