The dreaded question

Yesterday, we were watching our neighbor for her mama to have an ultrasound. We were discussing where Cynthia was and why.
M: They are going to take pictures and look at the new baby.
L: The baby in Miss Cynthia's belly?
M: Yes
L: Like I was in your belly?
M: Yes
L: How did I get in your belly?
(Oh boy!)
M: Well......
L: Was I teeny, tiny and you swallowed me?
M: I'll explain it to you when you get a little bigger. (and daddy is home)