I don't understand why your mom won't take it to a rehabber. She won't have to pay anything, the rabbit will be going to someone experienced and will get vet care
There's nothing you can personally do for it if it has a broken leg, it neeeds professional care.
I hate to sound harsh, but if you don't find somewhere to take it it will probably die. Baby bunnies
are very fragile, especially wild ones and especially injured wild ones. If it's bleeding from the nose it has a broken leg then it needs vet care. Plus, how are you going to feed it if it doesn't eat solid foods? You can't just feed them cows milk because they're digestive systems can't handle it.
I'm sorry, maybe if it was perfectly healthy I would say you had a chance to raise it yourself. But how would you feel if you had a broken leg and no one treated it?
I would talk to your mom and try to find a rehaber, if you want the rabbit to have a better chance to survive.