If you want any games for switch to work as intended, without a bunch of lag or any major fiddling to get that one specific game to work, switch/2 is sadly the only way to go.

As for the deck route, absolutely depends on various things. Is she okay with piracy and will she know? Do y’all plan on using it just for switch emulation or are there other games on other consoles/Steam/other storefronts that are gonna be emulated/installed? If yes to questions like that, deck would be the way to go. More bang for your buck due to not being limited to a single games ecosystem.

Also, another thing to think about, is that there are current, IIRC, Zer0 switch 2 emulators that can do much of anything, so you’d have to emulate the switch 1 version of games on something like Ryubing Ryujinx. Do you wanna wait for a switch 2 emulator that might not be able to run that less popular title you like because they’re focusing on the big triple AAA titles? Good to keep this in mind, IMO.