Could it be worse then a sprain what do you do about it?

I know someone who took a steal toed boot to her ankle pretty hard on accident. She went to the emergency room the same night it heppened. They said they couldnt see any breaks and it was just sprained. However, this was three nights ago and she still wakes up in the middle of the night from pain. Could it be worse then a sprain what do you do about it? Shes on pain reliever, an air cast, and crutches