If you are no longer tied into vacations...having her able to drive in a pinch is nice but does the need to trade off regularly become a deal killer?
- 2 week 3000mile trip typically means some long driving days where trading out driving duties is really nice.
- 6 month 5000 mile trip...no need to do more than 3hr in a day.
I do think having her learn to drive it is good so if something happens to you, she isn't trapped but you could do an occasional practice drive to get her used to it under easy conditions (say rural freeway with minimal traffic and not complications from mountains or lots of sharp corners). Good chance if she got used to the 5er, she will quickly pick up on driving the MH.