Julie, I think you want to look for hardy begonia, Begonia grandis. It's often a passalong plant, as it was in your family, but named cultivars ("Heron's Pirouette" is one) have been developed that may be found in nurseries or online sources.
lol...you share the same name as a designer in our area that loves to use Begonia grandis in her designs.
why not take cuttings of the begonias you have? they are easy to root with a little care and that would insure you have the same plant
Thanks Doug & April, i should have thought of that! I will try cuttings today. I should have looked it up Doug, thanks
VERY PRETTY ..