I have a friend who had a bad ankle sprain 5 weeks with severe swelling, the swelling has not gone down and now her foot is Red. Why hasn't the swelling gone down and her foot Red?
Concerned

How do you know it isn't broken? Why isn't your friend "concerned". Go to the doctor or ER.

As was suggested... did they NOT go see a doctor? There is so much that could be wrong well beyond a sprain...fractures, torn ligaments, torn muscle tissue, nerve damage as just a few possibles.

Because after 5 weeks, it is not just a sprain and needs medical attention, go see a doctor