I think peroxide works well, but recommend bacitracin, which is an antibiotic cream...more of a schmear, really, but it is ususally used in hospitals. Also, alcohol is good, but it burns. If you pour peroxide on it, and it bubbles, then that is a sign of infection. You can folow up with alcohol, but, like I said, it burns. Bactine is good, because it has an anesthetic in it as well...they still make it, too (if you're a lot younger than I am, then you won't remember Bactine. Trust me, look for it in the grocery).
Good luck. If the infectin doesn't clear up in a day or two, then you have no choice. Go to the doctor. Your mum knowing is a lot less stressful than losing a limb.
Let us know how you do.