I'm sorry to hear about your mum and what she is going through right now. My dad went through the same fatigue issues as well and they are quite common really. Like your mum also, my dad never had chemo at all so we couldn't put his fatigue down to that either. He also used to nap a lot duirng the day and would get very tired quite quickly. And again like your mum, he was eating what we thought were enough calories and although he would eat less than he would before he was diagnosed, he was still eating a reasonable amount. He also used to take some dietary supplemements such as the Ensure drinks to help as well with keeping his calorie intake up. Is your mum taking any of these tyopes of drinks such as Boost or Ensure?
Here is a link that contains quite a bit of info about cancer and fatigue, and I hope that it will be of use to you.
http://www.macmillan.org.uk/Cancerinfor … tigue.aspx
Please keep us updated on how things go for your mum, we are here for you.
Best wishes to you and your mum,