How many times can a molly fish give birth?

[*Candy*]

I want to know how many times can a molly fish have babies. There is one in the tank thats black and its about a week old. The female fish looks pregnant again. Also i want to know if all mollies the same or are there certain breeds and there names. Mine are black and white.

 

[dgm]

The same "breed". They give birth until they die.