I'm having some problems with a girl who lives on my street ((read the whole story, please))?

This sounds like a serious problem, but one that parents won't take seriously. You need an adult who can intervene on your behalf. Is there any chance that an adult, like myself, could talk to Nicki's parents for you? Another possibility, if you want to protect the kittens first, is to take the mother and kittens to a shelter or vet and explain the situation. Most people who work with animals are very understanding and I'm sure that they will care for the kittens until they are old enough to adopt and then return the mother to Laura. The shelter will appreciate your concern and do what is best for the cats. In the meantime, the shelter and vet might also be able to discern the genealogy of the kittens and maybe back up Laura's claims that her car fathered them. They might even be able to actually do a paternity test, if they are truly concerned. Remember, when you take the kittens to the vet or shelter, be calm. Speak slowly and rationally. Don't give a lot of background about Nikki or your past. Simply express concern for the kittens. That way, when, and if, Nikki gets involved, she will look like the emotionally motivated one who cares little about the kittens and more about hurting you and Laura. Never express anger or hatred about Nikki. This is very important because it will be the only way to get the credibility you need. Trust me, when adults outside your family get involved, they will see the truth and protect the right parties. Good luck!