There was actually a Terra doppelgänger who joined the Titans in the 90s. She was engineered to be genetically identical to the original Terra. So, she was technically "alive" before Flashpoint hit and a member of the Titans up until at least the 2000s. She also joined the Outsiders. Actually, its unclear whether this Terra is the original Terra or the doppelgänger (with the original still dead and buried).