My daughter has a rotten tooth in the back and now there is abig bump coming out the side of her gum I can't get to the dentist till friday what to do?

Infected Tooth. As long as the lump is not growing and there are no problems with neck swelling and there are no problems with swallowing and there are no problems with breathing ... Ok to wait a few days. If any of these develop, go see her pediatrician right away. If unable to see, go to er for prompt treatment. If all the above negative, ok to wait a few days to see her dentist.
Abscess. This sounds like an abscess which needs to be seen by a dentist asap. Patients with tooth abscesses need antibiotics followed by a root canal or removal of the tooth. Without treatment, the infection can spread to the bones and blood. Sometimes, patients can call the dentist before hand and get the best course of action directly from the dentist. But people should not delay seeking treatment.
Antibiotics. See a doctor to get some antibiotics. If there is any difficulty breathing, fevers or severe swelling o the face, go straight to the er. Good luck.
Call your dentist. If your child has a badly decayed tooth that has abscessed, the infection needs immediate attention. Ask your dentist to see her asap or refer you to someone who can.