It sounds like it could be MRSA (aka staph infection, they are very difficult to keep from reoccurring) or impetigo. Either way, she needs to see the doctor. You'll need to reschedule the eye surgery until this is sorted out and treated.
Toss your combs, never use the same ones or brushes used on them on anyone else, they each need their own. Wash everything down in bleach, wash clothing, bedding and towels separately from the rest of the family's. Whatever they had/have, she was reinfected.
The best thing you can do to prevent the spread of the infection, and to keep you and your family from getting it, is to practice excellent hygiene. Keep your hands washed, gloves on when treating the wound, do not share personal items, such as soaps, towels, or clothing. If someone does get it, make sure to keep the wound covered. MRSA is extremely contagious.
Lastly, if it is indeed MRSA on their scalps be very, very conscientious about treating it. My brother had it a few years ago on the back of his head, he was hospitalized 8 or 9 days. The doctors were extremely concerned about it as the nature of MRSA is to burrow downward, they were afraid it would go to his brain.
Wish you the best!