how to make girls...

Zacks conversation with the neighbor today went like this:
Zack to neighbor lady: I want a baby sister.
Neighbor: well maybe someday when you grow up you will have a little girl.
Zack: Nope, I don't know how to make baby girls...
Neighbor: well, maybe you should ask your mommy how.

I informed her that I obviously do not know how to make baby girls either. She was no help- she has two boys....
And (for the record) NO I am not pregnant-