Does she feed live all the time? Does she know if the rats are fully constricted and dead before the snake begins to swallow its prey? My current guess is the rats are still partially alive at least while being swallowed.
If the meal was much larger than normal, leave the snake alone for an extra 2-4 days to digest. If the snake can handle it, the meal will get digested and will take a longer than usual. If a regurge happens, wait 10-14 days before offering another meal and leave the snake alone as if it were just brought home and settling in. The snake needs time to build it's digestive system back up before eating again.