Hello & welcome.....If it's tiny little black specks (Like pepper), it's flea poop!! If she's allergic to the bites, they will turn to sores...Do you use a monthly flea preventative?
The pimple like sores with heads could already indicate a infection....Usually staph!
It would be better to treat it now before it gets worse, but I understand your situation..Do you have anyone that could take her to the Vet for you? Some Vets will let you do a payment plan...You could call around and ask a few.....
Until you can get her seen, I'd put an OTC antibiotic cream or ointment on them.....Take care and please keep us updated on her.....Karla
My dog gets the same thing and we have been told it's an allergic reaction. We treat it with benedryl and when it gets really bad it's treated with steroids.