If its in fact a mouse regurge after 5 days then be glad the snake threw it up.
This is a sign of bad temps if the mouse has not digested after 5 days and if it were to stay in her, the mouse would only rot in the stomach.
That would be the only other reason she would still have a mouse in her belly after 5 days. What are your temps and how are you tracking them? Oh, and are you using a heat lamp or an UTH?