Depends. Can she follow directions?
Try the following...
Don't reach for anything.
If you need to adjust your seat position, or need to get a drink, or... let me (the captain) know so I can be prepared, or even pull over and stop.
The captain needs to know how to ride a bike, but the stoker there is a bit more flexibility.
Try it, rent one of those tandems. If you do have a problem that seems to be unfixable, then I change my answer to no. If however you have fun and it seems like something you like, GREAT!