Need advice how to resolve 20 years distance/detachment with sister..?

Bury the past, starting over just takes a few steps in a row. Stop by a flower shop and take her flowers and chocolates for the family and tell her you were in the neighborhood. It's never too late, whether it's family, friends, or whomever. Too much time has gone by to look back and miss the present and the future. Let bygones be bygones, that'll be easy since you forgot what they were!!! Good luck!