Starting Saturday I'm engaged in the same project with my wife, a never ever about your age. Here's how I'm approaching it:
1. Lessen the pressure. We're borrowing clothes from my cousin's wife who's similar body, using language like "if you end up liking it, we could..." Not using language that indicates I think she needs to be very good at all. And if she doesn't like it, it's no big deal.
2. Introducing ideas of skiing/snowboarding friends we could do a group trip with, priming her to want to enjoy it even more. Her best friend loves to snowboard, and it'd be great thing to do with her.
3. Lessons. She's out with me for 4 days, 3 of those in ski school, which is offered as a package and is a (in Vail Resorts terms) a very good deal. Teaching her myself is a fool's errand as I'm no pro and it'll just make her feel like I'm criticizing her.
4. Comfortable resort. We're doing Beaver Creek in part because that's where we have hotel points, but also because everything else around it is easy. Not having to worry about where to eat, driving, etc. is big. The fewer added stresses, the more she can focus on how good it feels to make a lot of progress in her lessons, feel the cool air against her cheeks, and hear the snow's schhtttt sound. I've also heard their ski school is good, and she won't need a huge mountain.
5. Making it not just about skiing. My first instinct is to be first on the lift, eat early or late to avoid crowds, come in fairly late, then crash at about 8:30pm. But adding some nice dinner reservations, apre ski stuff, etc. will hopefully make her enjoy the general experience around skiing.
6. Going during a holiday from work. Of course "crowds" don't sound appealing, but I suspect allowing her not to worry about work as much will be good for avoiding stress and crowds won't matter as much if she's in ski school learning during the crowded times.
7. Last, I'm sometimes a bit of a whiner in the moment by my nature. Even on good days I'll bitch about my feet hurting, having to take a shuttle to get dinner, it being too hot/windy/cold/groups splitting into the singles line (just kidding). I make no promises, but I'll try my damnedest to be optimistic and positive about my own experiences. Nothing sets the mood like a negative nancy.