Sounds like a great pairing of bikes to me anything smaller might be a too small for highway use. If she is comfortable on the bike then it should be no problem, she should take a MSF course though. I'm not sure how long you have been riding but I would suggest that you consider taking the course as well. It's funny but riders who have logged lots of miles tend to get complacent and the MSF courses serve to remind people what to watch for out on the road and to re-hone skills.
Dave
Dave