You should keep track of her breeding dates, so you can estimate her foaling date, which averages 11.5 months from when she was bred.
During her pregnancy, you will want to keep up her health care and vaccinate her for Rhino at 5, 7, and 9 months of gestation. Keep records of these events.
Recording her foaling date will help you in predicting when she should come back into heat: within 9 to 10 days.
Additionally, you may want to keep her previous years' breeding records - days in heat, how she teased, when she was bred, etc. This can be good information for the next year, as most mares follow similar cycles from year to year.
