If the games you're looking to play are competitive multiplayer games, those usually actively fight Linux users. Games like Valorant, Apex Legends, and Fortnite are all broken on Linux due to their invasive anti-cheat software. There are exceptions to this, of course. The devs of Marvel Rivals, for example, have said that they don't have a problem with players on Linux.
For.anything else, odds are it will work fine. You can always check protondb.com to see if, and how well, your games work under Linux.
I've been Linux-only for a few years now, and I haven't had issues playing anything yet, besides maybe some minor tweaks.
Mods can be more complicated, but I don't have much experience with that. I do believe Nexus Mods are working of a project to simplify game mods under Linux, so hopefully that works out well.
For there to be a flight risk, there would have to be a crime being committed. She's already done the time for her past conviction, so there's nothing to flee, and thus no flight risk.
Her leaving the country and coming back is not a crime when she has a valid visa allowing her to do that.