My Mother Helped Her Cousin While She Was Sick For

My mother helped her cousin while she was sick for a few months. Within that, her cousin never told the family she had hiv. My mother along with the family helped her bathe & changed her & such. For boxing day my mother helped her bathe this was her first time washing by her vagina area, but she used a washrag & soap an washed by her vagina & such & i know vagina fluids contains the disease. My mother did not use any gloves to do that task. It was only today she was made aware of the situation. She immediately went to he health centre for a test & the result was negative. She has to go back 3 months from now & im scared. Im only 16 & I dont want to lose my mother she is a hardworking lady who did nothing to deserve this. So is the disease able to be contracted by the washing of her vagina in the bathtub with soap & water. (Ps she has no cuts on her hand) Im very worried atm & i need answers!