Dahlia’s mentioned a lot alongside Arcite, namely since they were the last two Redjacks of the original eleven:
[u.1:01] Shaxx is pulling Arcite from the field.
[u.2:01] Not Dahlia? She’s a natural for modifying foundry gear. Her combat numbers are through the roof.
[u.1:02] You can fistfight Shaxx over it, if you want.
[u.2:02] Dahlia’s the last ‘jack standing, then. Maybe it’s for the best. New frames have trouble data-linking with her and Arcite. The two of them have been around since the beginning, and their heuristic systems keep rewriting everything.
Where Arcite was pulled to be Crucible Quartermaster, Dahlia stayed on the field. She presumably lived through the Red War, especially if she really is accessing & altering new frames.