You could be having the infection too but could remain asymptomatic or your immunity could be good enough to keep it under check and may not be true in her case. She could be showing the symptoms and would generally get worse after intercourse. Both of you need to be treated simultaneously and till then it is better if you can use barrier methods of contraception like condoms. Homeopathic Medicine has very good remedies like Caladium, Acid nit, Rhus tox etc to get rid of the infection.