My cat has a lump under her ear?

the lump could be an infection or an abcess or a very serious tumor. I advise you to get some one to help you get her to the vet other than your mom. keep her in the house from now on because if she plays with the tomcats and they scratch it open it can get infected and her ear will fall off or have to be amputated. If it is any thing serious then she will probably be deaf. sorry i feel bad for you and your cat.