How small a space does it need to fit in? Where are you going to ride the bike: hills, trails, road? Some of these fat tire folding bikes don't fold down very small. Other folding bikes to look at are GoCycle, Brompton, Bike Friday, and Tern.
Most of our riding will be in National and State park campgrounds, which can get hilly. Maybe some mild off road in those places.
She likes idea of Liberty etrike for herself. Way more stable. It also comes apart into two 25-lb halves that can easily fit under the RV. Much more limited, but I plan to be a bit more adventurous.
I have a rack that would handle either Rad mini or XP2.0. Thanks for tip on other foldables. Any opinions on Rad or XP?
Any motor will handle short hills. Long steep hills may require a mid-drive ebike. I don't know much about trikes. They can be tippy going around corners and you have to take them slow. They are also wider and stick out into the road more if there isn't a bike lane or shoulder. There is such a thing as a leaning trike that gets around the tipping problem.
I don't own a Rad or XP, but there are subforums on this site for owners of those bikes. They are both sub $2K bikes and I think the Lectric is sub $1K. This is considered the low end of ebikes and there will be compromises in the quality of the components and frame of the bike to meet that price point. Mid-range ebikes cost between $2K - $5K and high end bikes can cost up to $10K. That said, the Rad bikes are very popular and there are a lot of accessories available for them. The Lectric is mostly popular because of its price, but may be a good value for what you are paying.
I do own a Brompton Electric. It has the smallest fold available, but it is designed for UK regulations and the motor assist cuts out at 15.8 mph. It is so small and light that you can easily carry it into a restaurant with you and tuck it under the table. However, it is a lot more expensive than the other options you are looking at.
The eTrike looks good and should aid stability on paths/roads, but off-road, that extra wheel might make it feel more unstable rather than less. Especially if you don't have suspension to absorb the bumps. Its basically another wheel to hit every passing bump/tree root and that will have an affect on the handling.
If I was you I'd just double check its off-road abilities.