It sounds like you're looking at everything in a very healthy way. I wonder if it would be helpful for her to come here, to see that there are many other married people who happily support their spouses's relationship(s) with others?
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.