Welcome to Just Answer. Many women who are past menopause will bleed during intercourse. With menopause comes a decrease in estrogen production which thins vaginal tissues and can cause bleeding from mechanical friction during intercourse. Bleeding is only a big concern if she should have an infection such as hepatitis or HIV. If you have both been tested and are monogamous, then there is not a problem.
She can ask her gynecologist about estrogen cream to apply to her vagina. The cream will improve the health of the vaginal and urethral tissue without causing the systemic effects of oral hormones. Healthy vaginal tissue should not bleed during intercourse. She may need a gyn checkup anyway, to make sure her cervix is healthy and has no polyps or erosions (another cause of vaginal bleeding during intercourse). Meanwhile, be sure to use plenty of lubricant, although even that may not be enough to prevent bleeding.