I think the first thing is to ask what sort of ride she wants to do and make sure that's what you're doing.
My spouse and I are a pretty good match for speed, but it irks me sometimes that he only ever wants to do his kind of ride - long highway rides on road bikes - and is only rarely willing to do other kinds of cycling that I enjoy, such as urban exploration tours. On the rare occasions that I talk him into one, he'll get into a sulk and start going slower and slower, forcing me to keep stopping at intersections to wait for him. I'm quite willing to come along on his highway rides, so this irritates me.
Compromise is a must.