I am sorry to hear about your friend, this must be such a difficult time for you.
There can be many different reasons for legs to become swollen. If your friends doctors are unaware of the swelling it is important that they are told about this, so they can assess her and the cause.
The most common cause for leg swelling is oedema (a build up of fluid) that can be caused as a result of the cancer itself. Sometimes fluid can build up in the legs because one of the bodies organs such as the heart or kidneys isn't working properly. One swollen leg may be caused by a blood clot but the leg will also often be hot to touch, red and sometimes painful as well.
As I say the doctors involved in your friends care need to know about any changes in symptoms so they can best assess and manage any symptoms she may have.
