How many babies do you need to get the first family? After the first family how many babies do you need to get the second one... I need two babies and two families for my quest so how many total babies do I need... I need to know how many birthstones I will need.

You need to get five babies first, to unlock the ability to attract the families. As long as you've had five of the baby spotted, you will attract one family for every baby you've had spotted.

1 baby =1 family AFTER the 1st

I'm not quite sure what you are referring to by "the 1st", Joy?  You do need to attract five babies first before you can get the families. From the left hand panel in the Babies tab of the wildlife guide:

"Returning Babies! If you are lucky enough to have had 5 of the same Baby Wildlife spotted in your Garden, you will begin to get Mother and Baby returning to your Garden together! Each Mother and Baby will return to your Garden once, and to attract them back, simply set up your Garden to attract the adult as normal."

Claire, after the  5th baby is spotted, then you get 1st family after that for every 1 baby your get 1 family , hence 1 baby =1 family due... 10 Adult wildlife plants 1 baby,, so 50 adults are needed to plant 5 babies...

OK, that's a bit clearer. Your first post seemed to be contradicting mine, given the brevity and the way it was phrased. I did say one baby per family in my first post, so I suppose I simply wasn't quite sure why you'd be repeating that.

Thank you for clarifying your intended meaning.