There are a lot of animal experts, girlfriend experts, allergy specialists, and life experts on this forum.

I'm highly allergic to cats. My wife loves cats (so do I, just not their allergens). Fortunately for her we have a large house and the cats rule the upstairs and I just dont go up there. Separate ac and filtration for both levels of the house. It's still far from ideal as part of the house is useless to me and the cats never truly get to be part of the family. Depending on your girlfriends allergy no amount of pills or air filters may allow her to live a decent quality of life with them. So if you dont have enough space for both you have to pick which one makes the most sense for your life. It will suck if you have to rehome them. All you can do is be responsible and find them as good of a home as you can. Good luck and ignore the pinside medical and life experts.

I've had 10 years of shots and am now on the immunity drops instead. No amount of shots or medicine would allow me to live in anything other then misery directly with cats. People that get a little stuffy are mildly allergic to cats at best. If I'm in a room with a cat for more then 10 minutes my eyes start burning, my nose starts running, and my throat starts feeling tight. The symptoms keep getting worse every minute from there on. It all just depends on the OPs girlfriends sensitivity level. Any one that says take a pill or buy an air filter has no clue what serious allergies are.

Life gets in the way of a lot of things. There was a family recently that we helped find a home for their large dog due to one of their moms being elderly and having to live with them or go to a nursing home. They chose to care for the parent at home due to them not being able to afford a decent nursing home and not wanting to stuff her in a bad one to wait for death. The parent is highly allergic and their was major concerns about the dog knocking her over which in the parents condition could be deadly. Lots of good people have to make very hard difficult decisions every day in life. But be sure to keep waving your finger and judging them.