I think I am about as lucky as you can get. My fiancee is one of my students. She loves aikido and it is quality time for us. Before she started though, it was a little rough for me to be gone so much (I have a 40 mile commute to my dojo...by choice
So when she expressed interest I welcomed her wholeheartedly. I think one problem I have seen with my peers is that they tend to want to "persuade" their significant others into practicing aikido and then develop unreasonable expectations for them. A gokyu student and a dan rank tend to have different goals and levels of commitment. So, I believe to make relationships like this work, the "shugyo" student must put themselves in their spouses shoes. Step back from everything, observe, and of course breathe.