What Should I Do About A Hard, Red, Golf Ball-sized Lump At The Injection Site After Injecting Methamphetamine 3 Days Ago, Despite Taking Amoxicillin?

My daughter injected meth three days ago and now even though she s taking 800 or so mg of amoxicillin she has a very hard golf ball size knot on the site and redness but it s very hard to the touch what can I do to help her it was a relapse after 8 months sober