Suggest Remedy For Spot On Vagina

Hello, my partner has a spot on her vagina and I would like to know what it is please? She has never had it before! We have been sleeping together for 5months and she has just got it. Before we got together I was checked and had nothing wrong with me as she never had anything too! She is the only person I have slept with in 5months. WHAT CAN IT BE? HELP PLEASE..!