What Causes White Vaginal Discharge Along With Itching In Vagina Of A Child?

My daughter is neatly seven years old. She has had a head cold the past day or so. But I have noticed her scratching a lot over her underwear. H She has thick white discharge and compliaing of very itchy vagina two days too. I m giving her probiotics every day anyway? Canes ten applied and helps a bit, bug pharmacist says children under 12 do not get vaginal thrush so I shouldn t be using canesten. I took her to gp to exclude UTI and just check for her cold. Sample came back normal. Am I safe to use canesten on her to relieve sypmtoms, as it appears to me it is thrush accompying her cold. Worried mum