Should we live selfish lives

I have been chatting to a long standing friend. She has a daughter with severe mental health issues that are unlikely to improve. She also has a very elderly mother who's health is failing. Her partner is about to retire and they have made definite plans to move to sunnier climates for the foreseeable future. She says "you only live once and have to do what makes you happy. She thinks I'm being a Martyr because I couldn't in all conscious leave my son and his family of three little ones to cope with his wife's serious illness and the probable horrific outcome. She didn't agree with me and says my own happiness should come first. I'm not being judgemental (I may be a little envious) she's the kindest most loveliest person and very popular with her own and my family. She also said that if it was one of our children we would be saying "you go and make a life for yourself. No matter what was happening here" she said in my place she wouldn't let it change her plans. That our children are adults and must take whatever life throws at them. I don't want to know who's right or wrong. I just interested in what your thoughts are