I wouldn't really think so if she has been to the doctors and discussed this. Sometimes pain during sex can be psychological. She also can look into vulvodynia. https://www.mayoclinic.org/diseases-conditions/vulvodynia/symptoms-causes/syc-20353423. have her continue to update her doctor.
Has she been to see the doctor?
The doctor may prescribe metronidazole to treat vaginal infection, Usually, metronidazole can be taken orally. Sometime metronidazole can also be inserted directly into the vagina with a topical gel.
Since the doctor has checked her and had a reasonable explanation for her symptoms, why are you still fretting? Change her choices in taking care of her period and see if it improves.