The alps is chock full of touristy stuff that’s not biking:
Walking
Lakeside strolls
Spa hotels
Nice restaurants
Towns (with associated amenities)
Museums
Art galleries
Courses for painting, or whatever you want
Craft shops/fairs
Loads of stuff. It’s like the Lakes or North Wales – not just about the outdoor pursuits.
You might have to choose where you go carefully. What does she like? Sailing? Eating? Swimming? Etc.
She might not mind if you go alone, but she might really enjoy a trip herself, and the fact that you want to do something nice for her! If she doesnt’ mind being away from you but doesn’t want to go to the Alps, you could plan (together) something else nice for her to do elsewhere. Got any distant relatives, that kind of thing?