The Plum Tree Family Tree Tool: Developers Wanted

Hey @ThePlumbob or anyother who knows anything about this. First of all I gotta say I LOVE the Plum Tree App. It has all the features I need and want, well almost. I am currently at Generation 6 and started with 6 different families. So basically I have 6 different legacie bloodlines. Of course they did marry eachother at some point and now I have the problem that I have to duplicate certain sims several of times. I tried to copy them into another tree but nothng seems to work. So my question is. Do i have to do all Sims again by scrap or is there a method to copy the sims from a tree to another. So I have them in both.