Well let's see... I went touring with my romantic partner over thirty years ago and we are still together, so I must be doing something right. I have three suggestions.
A) make sure that her bike is not too heavy to keep her from becoming discouraged. B) Start out with short days, don't blow her out with long days. C) Make sure that you take a pocket shower. Nothing worse for the new cyclist/ tourist trying to sleep while all sweaty.