My sister needs a new doctor. Where do I start?

DEAR CARALLEL: My sister and I are all each other has. Our mother passed away when she was only 59 and since then it’s been the two of us (and our pets of course). That’s how it’s been for 26 years and counting and we’ve managed pretty well, if I do say so myself. Although my … My sister needs a new doctor. Where do I start?