2987 - Luornu Durgo is created in a lab by Brande Genetics. With no way to recreate the process she is given the memories of Brande's 11-year-old adopted daughter Luornu who had tragically died of a genetic disorder.
2990 - 14-year-old Luornu is present when the Legion of Super-Heroes saves her adopted father, but has to keep her powers secret.
2991- 15-year-old Luornu joins the Legion of Super-Heroes in their first recruitment drive, taking the name Triplicate Girl.
2996 - 20-year old Luornu sacrifices one of her duplicates to save Chuck Foster during the Legion of Super-Heroes fight in the Earthwar. She becomes Duo Damsel.
3000 - 24-year-old Luornu sends one of her bodies to take over Brande Industries from her father when the Legion of Super-Heroes disbands. The other goes with Querl Dox. He unlocks her ability to mass duplicate and she staffs Legion World.
3005 - 29-year-old Luornu brings the resources of Brande industries to Legion World when the Legion of Super-Heroes reforms. She rejoins with her other half, absorbing both sets of skills. Her original third form reimurges. She becomes Duplicate Girl.
3007 - 31-year-old Luornu moves Brande Industries in it's totality to Legion World.
Duplicate Girl (or Triplicate Girl, or Duo Damsel) is a quintessential member of the Legion of Super Heroes. Her powers are at once incredibly simply while also being a bold-faced assault on any semblance of realism... but those powers are almost secondary to her personality. The role she had as a sweet girl that would be a little flirty sometimes was WAY more important than the fact that she could split into multiple bodies. In fact, the exact number of bodies she can split into kept changing, which is why she's had so many different names. Her costume shifted constantly as well, and she's actually had quite a few widely different designs that were often of pretty high quality. In a lot of ways she's an excellent microcosm of everything fun about the Legion.
We deliberately included the idea that the number of bodies she is able to split into shifted over the years, necessitating the different names and probably the different costumes. We wanted to make sure we had her settle on being able to have TONS of bodies, because that's defintiely her most powerful configuration and the one we like the most, as well as the name Duplicate Girl, as it's the only name she's had that doesn't actually specify how many bodies she can split into.
Also, we wanted to make sure to keep her relationship with Bouncing Boy. It's adorable, and it's one of the best teen romances from those early years of comics.