It would be unlikely for a rip to not result in severe hematoma/bleeding, meaning a large bruise would form. I doubt it's a tear, but may be moreso something just cavitating - maybe a rib or something of the sort. She should take it as easy as possible and if it doesn't get better, she should probably go see a doctor. However, I wouldn't really worry about it quite yet. Just tell her to take some ibuprofen for the pain and potential swelling in the time being. That will help.