OMG HELP MY MOUSE IS PREGNET!!!!!!!!!!!?

ok so this will be her first litter, in her cage there is 2 other females and 1 male, the females sometimes fight, but there is never any blood or any dies or gets hert. should i leave all of the mice with her, or should i give her her own cage? i know that other females can be nannys, but the other 2 r not pregnat, and have never had babies before or seen a pinkie. also would the male kill the babies? the mlae is really nice, and has never bullied or done any harm to the females! thanks!