It sounds like you have a dilemma. The key words I hear here are "deal breaker", which is a warning light something is seriously wrong...
Take her to an RV dealer with lots of rigs with better toilets than the standard ones. Have an expert explain the difference between residential and RV toilets.
Now have her explain to you why she dislikes an RV toilet. My guess, being a gal myself, is she dislikes the fact you need to fill the bowl with water then flush by opening the valve to dump into the tank...I'm just guessing that grosses her out. They can be more difficult to clean to keep them from leaking but...I personally have no problems with an RV toilet. Once someone gets used to one...it beats the alternative--not having one at all!
Now do your homework and see what happens! In order for a couple to remain happy...both need to be secure about all the systems in a rolling home. If only one person is in the loop is therefore doing all the work...if that one person is ever not able to do it, even for a day or two...what will the other person do then?! Teach her how all the plumbing, electrical and heating systems work, help hooking and unhooking a toad, service all the wet bay items...don't stop there...she should have basic understanding of the chassis systems too and the really big one--at least know how to drive if not actually share in the driving. But, I realize that's a whole new bucket of worms to pick through.Good luck.
