They can't see either in x-rays, both are soft tissue injuries unless she dislocated it.
I'm not big on doctors either, it takes a major incapacitation to get me to one, but I might go in this case, both because the knee is an important thing, and because they may help it heal ~faster~.
Or maybe not. I just know that sometimes when you wrench knees, you mess up the cartilages that hold the knee together and it's never really right again without orthoscopic surgery to clean it out. I hope that's not the case.
If it were me, I'd wrap it tight, just to keep too much fluid and swelling from collecting there. And lots of anti-inflammatories... Bute her ;~D