@SarahGen-- Yes, post menopausal vaginal discharge is normal. It has to do with estrogen and the pH level of the vagina.
After menopause, estrogen levels drop. This change triggers a change in the pH levels of the vagina, it goes from being acidic to alkaline. When an environment is acidic, it prevents many bacteria from growing. So when it shifts to an alkaline pH, the environment becomes more suitable for the growth of bacteria. It's this bacterial growth that leads to discharge and also odor.
There are antibacterial vaginal creams that can be used if the discharge and odor become very uncomfortable. A gynecologist can prescribe one.