Hello, thanks for using HCM.
From the description it is more likely that she has an infection. Genital tract infections could be transmitted through sex but not all are sexually transmitted.
Itchy whitish discharges are most often than not associated with a yeast infection and is not thought to be sexually transmissible. Yeast infection are common in women using hormonal
contraceptives, antiseptic soaps and creams for vaginal cleaning, poor anal hygiene, pregnant women etc. Treatment in her case will require antifungal drug fluconazole
and antifungal cream and some antihistamine like chlorpheniramine
However, other causes such as Trich infection has to be excluded. Trich is sexually transmissible but in men, it may present with no symptoms. Trich also can explain the symptoms she has.
So i will advice she sees her doctor for a vaginal smear tests and appropriate treatment.
Best regards and hope this helps