22 years ago - Miriam Delgado is born into poverty in Brazil.
12 years ago - 10-year-old Miriam is orphaned, and is left alone on the streets of Rio.
7 years ago - 15-year-old Miriam's illusion-powers manifest, and she uses them to come to America.
6 years ago - 16-year-old Miriam is joins Flamebird's Titans as Mirage. She dies in the Quroc bombing.
Marv Wolfman's Team Titans (That's Team Titans, not Teen) was a bit of a storytelling long ball. A Titans team from the future sent back in time to stop Donna Troy's son from growing up into an evil deity. Once that story was completed, the team stuck around and slowly had their backstory picked apart by various alternate timelines, until Zero Hour retconned their history completely, making them brainwashed sleeper agents. In the process, Mirage managed to use her illusion powers to pretend to be Starfire and sleep with Nightwing without his consent, and then was raped by an evil future version of Nightwing (literally called Deathwing) and bore his child....
Honestly, at some point, it becomes worse than just nonsense, it becomes offensive. It happens more often than you would think, that a character is completely stripped of everything that made them who they were, but they're kept around anyway.
What remained of her story was that she was a street kid from Rio whose activated Metagene allowed her to come to America. At least with that, we have the chance to create a working version of the character. She's younger so she can be a real Teen Titan. She has a cool look and fun, unique powers, and It feels like allowing her to have her time in the sun and be a hero, even for a little bit, is the least we owe her.