If you can't take your dog to the hospital you could spray benedryl on the spot, it doesn't hurt. I use to work in an animal hospital as a vet tech and it you think its ringworm, I'll let u in on a little secret. Athlete's foot cream has an antifungul in it that doesn't hurt your animal but with ringworm being a fungal it will take care of the problem. If its allergies then you need to visit your vet for a steriod shot, which will help.
It could possible be a ringworm but she would have to be diagnosed by a vet it's not too serious just be sure to find out soon it is possible for it to spread to humans while petting or grooming the dog. you may want to look up symptoms online just to be safe
Most likely it is an allergy and putting the dog on prednisone will help. Only a vet can give you the meds. Also he can administer a shot of cortizone that will help. The dog will uninate more from the prednisone due to an excelerated intake of water ( they drink more). This is normally seasonal and will be a regular issue with your dog. Only a Veterinarian can diagnose if this is truly an allergy, but most likely it is from grass.