Fibroids do not bleed after menopause. Once your mother goes through the menopause, the bleeding should completely stop. Fibroids do not have any effect on when one attains menopause i.e. it does not delay menopause.
If the bleeding is heavy, she can take some medication to reduce the amount of blood flow, which her doctor can prescribe.
However, if the bleeding is very heavy and is not being controlled by medications, she might as well have a hysterectomy.