Is it permissible for my mother, who is 51 years old and suffers from a fibroid tumor and bleeding throughout the month, to pray and fast, and how should she do that?

Scholars differed regarding the age of menopause for women, and the correct view is that there is no fixed limit for it, and it varies among women. So, whenever a woman sees menstruation, she is considered menstruating. If your mother has reached menopause and her menstruation has ceased, then she became ill and blood flowed, this blood is not menses. She must take precautions and perform ablution for every prayer. However, if this occurred before she reached menopause, she must consider her usual menstrual days as menstruation, during which she abstains from prayer. After those days, she should purify herself and pray, even if blood continues to flow, because it is not menstrual blood. If the flowing blood is from a wound, its owner is pure and can pray and fast. If this is not clear, then she falls under the ruling of a woman with irregular bleeding (mustahadah): she abstains [from prayer and fasting] for the duration of her usual menstrual period, then she prays and fasts, even with the presence of blood.