Hello, Welcome to HCM, The history and symptoms of your step daughter are suggestive of fungal infection which has lead to greyish white discharge, cuts on vagina, swollen vagina, and the foul smelling discharge. The fungus are the normal comensals female genitals which are kept under control by the helpful organism, when ever there is a imbalance in the environment it will leads to multiplication of the fungus and produces the symptoms. The fungus will sustain for longer period of time in wet and moist condition. The affected area should be kept dry and clean. Your step daughter requires a topical antifungal cream, good hygiene should be maintained. If the symptoms are not coming down she may require oral antifungal drugs. Thank you.