Any recommendations on easy trails that aren't scary to take her tomorrow afternoon?
I don't know about your wife, but my wife has never really ridden a bike over a mile. She rode around as a kid, but she doesn't have a good grasp on coasting with her pedals level, or how and when to shift, or how to properly brake or lean, or how to read a trail. I made the mistake of taking her on a trail that was above her level and she crashed and got hurt. Now she has a big mental block to learning to mountain bike. I realized I need to start super slow... baby steps...
What about a super simple paved trail like jordan river trail or mudock? It'll help her get used to the controls of the bike, and slowly ease into it. After that, find a super mellow two-track road or fire road.
I agree with samersen about Lambert being fun and not too technical. I do still feel it can be overwhelming for noobies. I took my wife there and she was still overwhelmed. Things I don't even notice really stood out and intimidated her.
Some of the littlest things can spook them (even though they're nothing for us). Aside from the loose gravel fire roads up there (not a good idea), everything is singletrack. Singletrack can be overwhelming for new riders. They're spending most of their time trying to stay in between the bushes on the trail, not hitting trees. They don't learn to look far ahead because they're worried about what's 2 feet in front of their tire. They don't learn to read the trail and just relax and ride.
Then there's the quick, tight turns in the trees (river, high bench, rodeo up, etc). Some of the turns are banked and that overwhelms a lot of brand new riders (rodeo, luge). They think they should stay upright through the berms and end up sliding down them. It's not super intuitive for them to learn into them. Some of the trails are super rocky and rough (middle, ruin, luge, brown dog). Don't get me wrong, I absolutely love lambert, but it might be a better 4th or 5th time place.
I'd start with a quick ride on a paved bike trail like jordan river or murdock trail. Then transition to a flat, wide fire road. Then slowly add a fire road with some easy climbs and descents. Then slowly transition to some flat singletrack, then work your way up to lambert then corner canyon then af canyon then moab.
The bar m area of moab has easier stuff.
I've also heard there's an easy loop here for kids. it ties in to upper anne's. I've never ridden it, but it may be good for beginners.
https://www.google.com/maps/dir//40.4861277,-111.8488785/@40.4859548,-111.8505618,849m/data=!3m1!1e3
