Personally I wouldn't force feed her at all unless she is losing weight and condition. It isn't uncommon for healthy ball pythons to go off feed for extended periods of time. Being alot of pythons normally go off feed for the period you described, i wouldn't worry tooo much. Just offer small prey items, even going as small as pinky rats. They as they take the small items, increase the number or size every 7-10 days.
Force feeding snakes puts alot of stress on them, and may make them less likely to eat on their own, or to keep the food down. Force feeding should be the last thing to do. If your snake keeps teh rat down then offer food normally in about 10 days, maybe live pinks or fuzzies