Pay Dirt Photo illustration by Slate. Photo by BrianAJackson/iStock/Getty Images Plus.  Our advice columnists have heard it all over the years—so we’re diving into the Pay Dirt archives to share classic letters with our readers.  Submit your own questions about money here . (It’s anonymous!)  Dear Pay Dirt, I am 58 years old and I need some advice regarding my sister. My mother lived in another country along with my sister, while I have lived in the U.S. for almost 40 years. I have been their sole financial support during this period. My mother passed away in 2019 and I have continued the same financial arrangement since then with my sister. The issue is that I had purchased a home for them to live in that I now would like to sell. My sister has only worked once in her life, briefly, and the rest of her time was spent taking care of my mother, who had health issues for many years. Earlier this year I had a conversation with my sister regarding selling the home and she became upset.…