I think your child has developed a dental abscess
around or below her tooth.This is causing the swelling on the gums and the recurrent pain in her tooth.Antibiotics will help temporarily but the problem will recur again.
Your child needs a dental Xray for a precise diagnosis.If she really has an abscess the abscess needs to be drained out or maybe the tooth needs to extracted.
Please consult a Paediatric dentist
if possible and get help. But you need to maintain perfect dental hygiene by brushing,flossing and regular mouthwash after food.
Hope this helps you out.Have a nice day