I am so sorry to hear about your Mum. I hate cancer!! Since she is already stage IV, the prognosis is not good. Please don't "wait" to get her started on treatment, if that is what she chooses to do. The sooner you can get started with something to fight this, the better.
My husband, like your Mum, was stage IV when diagnosed. His doctor started him on Torisel first, and that worked well for 8 months. The Torisel stopped working 6 weeks ago, and now he is on Sutent.
Dave says the Sutent makes him feel very tired, and he has lots of body aches and pains. He described it as feeling like he's "a walking bruise" or like someone had just hit him with a hammer all over his body. He is easily fatigued, and he sleeps a lot. His hands and feet have a tingling sensation, and his sense of touch seems a bit dull. He says he can't "feel" things like he used to. He has also developed very high blood pressure on Sutent and has had to start taking blood pressure medication. Everyone has different side effects to this stuff. But these are the ones Dave is having.
I hope this helps you. I will keep your Mum in my prayers.
Nancy