Here's some little plot bunnies for you if you're interested. Garrus secretly hacking into Shepard's omnitool before the run to the beam so even if he can't be there in person, he can at least try to be a voice on Shepard's shoulder. Garrus finding Shepard after the big Crucible shebang. And Garrus helping Shep with physical therapy as she gets used to her new legs and recovers!
Okay, I am posting these because I love them
Consider: Hacking her omnitool isn’t even really a secret. I mean, in the quiet party Garrus is cooking up lots of ways to booby trap Shep’s apartment to keep her safe, right? And when he’s caught, he goes sweetie, honey, love of my life, please, I just want to know you’re safe. And she gives in sometimes! So. Consider that he pulled this act re: the omnitool way before even the last mission.
Sweetheart, darling, love of my life, please, I just want to know that I can find you if we’re ever separated on a mission. And Shep does her ‘okay honey, if it’ll make you feel better’ routine but she wants the same kind of reassurance, you know? This concession is what ultimately saves her life after the whole beam run-in, because bullshit the Normandy left Sol completely, bullshit. They went back down to Earth and Garrus immediately pinged her omnitool.
Garrus also helping her deal with her new scars, probably. Telling her how amazing she looks. Who’d have thought he had a weakness for women with scars? They’re two of a kind. No, seriously, Shepard! -And maybe she doesn’t believe him and maybe she feels superficial and shallow for worrying about them, but it does make her feel better.