My Sister lives very close to my Mum. She is semi-retired in her 50's has no mortgage and is wealthy to the point where she doesn't have to work. My Mum is in her 70s in quite good health and financially secure, but after my dad died she has suffered terribly with loneliness. My Sister pops in and does odd jobs for her but that is it. She never take her out anywhere not even for lunch or a coffee. My Mum gave up much of her retirement to look after my Sister's two children when she returned to work, which meant my Sister had no childcare costs. Mum even did the school run for her as well as helping with taking them to activities etc. I can't believe how selfish my Sister is being and can't help but feel anger and resentment against her. I live 45 miles away and try and go to see my mum when I can. I am not wealthy, have health issues, I have to work and have a large mortgage after a separation, something my Sister said she would help me with, but then didn't. What makes matters worse if we go out as a family, my sister pays for herself only, I don't expect her to pay for me, but she never even pays for my mum even though in the past when my Sister had less money my parents often paid for extras like restaurant bills. We always spend Christmas together as a family, but my resentment is building and not sure I can cope with it this year, but I know my mum will be really upset. any advice?