Faraaidh and Sunnats of ghusal

Drinking water instead of gargling the mouth when making ghusal

Q: I performed fard ghusl. I performed the two fard of washing my whole body and putting water in my nose but before I rinsed my mouth, I drank a glass of water (to fulfill the obligation of gargling, as I was advised to drink a glass of water to fulfill the gargling) but then I forgot about rinsing my mouth. I rinsed my mouth the next day when I remembered but did not gargle as I had already drank water the day before it to suffice for gargling. So is the fard of washing the mouth now complete and my ghusl valid? 

Doubting if one gargled during ghusal

Q: Girl has been baaligh for about 5 years. She remembers being particular about doing ghusls from her menstruation but now shes getting doubts that sometimes she might have got yellow discharge in her menstruation days in the first few years and she didnt do ghusl again because she used to get yellow discharge in her paaki days (as white discharge when drying up can turn yellow) but now shes getting doubts and she used to have a bath eveyday (like washing her whole body) but cant remember if every time if she washed her nose and gargled so now how much qadha namaz should she pray coz her ghusl might be done at the wrong time.