I recommend GP just ask what kinds of things they might want. Or for a budding musician, a music store gift card would be really appreciated. I recommend Sweetwater (in the US.)
DAWs and MIDI controllers are sort of like keyboards, notebooks, or text editors. They all do the same things, but when they're your primary work surface little idiosyncrasies add up to flow-wrecking annoyances.
Lots of people love Logic, but I'm not one of them. It's not anything wrong with the product, it's just that Live clicks with my brain in a way that Logic doesn't. The Live interface has things arranged where I expect them to be. Logic hides everything in drawers.
That said, your teenager might be using Garage Band because they really like it, or they might use it because it's free and what they have. On the controller side, if they have experience with piano, they probably want a keyboard. If they don't, they might or might not want piano keys. If they do play piano, they will have preferences about key feel and size. My old piano muscle memory can't handle mini keyboards, for example.