it may not be an insect bite, but a boil that is coming up again and again. if recurrent it is called as chronic furunculosis
generally this occurs due to a bacteria that has formed nidus in the hair follicles and causes recurrent boil formation.
at present what she may need is a course of anti biotics on the prescription of a pediatrician
, too eradicate the infection and may be some topical antibiotic
the best way to prevent this is to maintain a good hygiene most importantly cleaning hands regularly with soap and water not for your daughter only but also for other family members.
other things like short and clean nail, regular use of soap while bathing, wearing clean clothes, not to play on dirty surfaces, using clean bed sheets etc may help decrease possibility of reinfection.
some times a person may get this from a close friend or family member who may be a asymptomatic carrier of the bacteria, through fomites like towels, bedsheets etc.
so you should get your family members screened for this also.
i hope these things help you in solving your problem
feel free to write to me in case u need any other advice