This is not my thing so I can't explain it very well but think the female counterparts to a Sugar Daddy... Basically, young females (18 - 25 or so) put themselves on sites dedicated to this looking for older male benefactors.

Swordfish will have to explain how it actually works but I do know of some findom types who also do this (and frankly I don't see much difference between the two other than the attitudes being different... I.e., findoms are "I deserve" while Sugar Babies are "Thank you for taking care of me Daddy").