When she came out of the coma, she knew she had to learn what had happened. Finding out Dom and Brian and Mia were on the run was one thing. Knowing Braga was still alive, even in jail, was another. While Letty could have evaded Witness Protection, she did not trust herself to evade Braga's empire.
The day someone shanked Braga in federal prison was a good one. She still didn't go, because while his Empire would fall to other druglords... her family had had years to cope with her being dead. Brian wasn't the kind to hold out false hope, and she'd still be in a coma when he up and bailed on the feds, rightly so, for Dom's sake.
Then something made her pay closer attention to the hell her former lover and family were up to, because one Luke Hobbs came to visit. She played dumb, not giving up a thin, then set a few favors into place. When Hobbs went chasing his rabbit, he was going to be followed, because there was one little guardian angel that wasn't letting any Fed she could stop get his hands on her family.