250 miles a month probably eats at least 25 hours a month with prep, planning, showering, etc. That's a lot of time and strain on a marriage. Somehow you need to make her feel she is more important than the riding. Figure that out. How about "dates", dinners together at the dinner table, not in front of the tv, planned excursions.
Good luck. My first wife had the same issues. It's one of the reasons I am on wife
#2 who is much more sympathetic and rides with me occasionally. One of the things we do is to plan our week. That way we know when we'll be together, how to plan things together (like gardening, of which my wife is a master and I am the hired help, but we're together and she sees me being involved in her stuff.)