Hi there
After 3 weeks, you will need to have this area examined by her Pediatrician or regular Dr. What might have started out as a spider bite might have a secondary infection now and will need both topical (like Altabax) and oral antibiotics (like Bactrim).
Sounds like you have done all the right things, but sometimes these bites need a little extra help to completely heal. Scarring is also a factor is she is not properly treated with antibiotics and also development of Cellulitis can begin as well...which is a serious infection that will have to be treated.
PLEASE NOTE: The $$$ that you have put down as a deposit will not go to me until you click "ACCEPT" after reading your answer. Otherwise, it will be held by JustAnswer.com and I will not receive credit for my time and efforts.
Please ask for clarification if needed.
Nurse
Over 17 years experience in many areas of Nursing. Both Hospital and Private Practice experience.