Devin: Devin returned back to Ashleigh in September, the months leading up to that spent travelling with Eli Halstead and Shy Murphy. He met the pair escaping from the prison Eli was as, where Devin was captured by inmates and used as zombie bait. He was in pretty bad shape when he showed up, but Abby took care of him and he healed over time. Over the last few months, he was also able to finally marry Abigail, thanks to Abe, and his father gave him his wedding ring, and Abby his mother's. His brother Zach just recently showed up. A less important note here is that Devin came back to two of his five dogs; Luke and Leia are at the resort.
Ryan: Ryan's insomnia has gotten worse over time. He rarely sleeps, is pretty withdrawn, and just does what he needs to do around the resort without saying much. He was recently reunited with Cecilia, who he felt responsible for when he lost track of her during the initial outbreak. Other than that, not too much to report.
Audrey: Audrey has been helping Abby in the medical unit, learning how to sew up people instead of fabric. She's been taught a few things over the last few months, and has been secretly spending a lot of personal time with Eli Halstead, who she has previous history with. Matt has no idea. Neither does Jo.
Christian: Chris has been getting by. He's grown up a lot over the last couple of months, but in order to keep his anxiety in check, he has been taking Xanax, which he looted from a pharmacy. The only person who knows he's taking the medication is Sonny (and now Kiley after a scene where she found his medication bottle), since he doesn't want people worrying that he's too unstable or something. He spends his time going on runs, worrying about Simone (or Li, as she goes by now), and helping take care of his niece, who he absolutely adores.
I'm sure there's more, buuuuut I can't think of it. I'll comment again if I think of anything new. ♥