my rat has a Injured foot?

Ok so my female rat (Judy) had this problem before. Her thumb got popped out of socket when she was playing and she had to have alot of meds and a few trips to the vet. i noticed a 2 days ago that she was holding her foot up and i thought it would go away, well yesterday it was a little more swollen , but today its still swollen? im going to wait till the morning but does it sound too serious? i hate thought of her being in pain..any tips? thanks.