Erhhmm...the light is so bad that I'm not even sure what she is, but she looks from the second picture like a danio. In which case she is not a livebearing fish, but will need to lay eggs which will then need to be fertilised by a male, otherwise she certainly won't be a mummy. And if she spots the eggs after laying she will not be a mummy either, but simply a wellfed fish. She may well be swelling up with eggs, but the whole mating thing has still got to happen. If my eyesight fails me, I do apologise.