Just went through this with my wife. She watched me ride Ducs for the last 12+ years and when i got the new 848 she was set on getting her own bike. She did shopping, test riding, and all the purchase paperwork. I was there to lend a few words of advise, but generally stayed out of it. I did suggest, and she tried a Triumph street triple, a Multistrada, and an older M750. In the end she was set on a new 696. While waiting for that she did her MSF course, and rode the 848 some. When she finally got her 696 she was in love. I think she is more excited about riding than I am on a daily basis.
It is a great beginners bike, but remember the price of entry and the inevitable drops are higher. Very pliable power, and as was mentioned, low end grunt that is making riding,especially around town much more fun. The other thing to consider is if she is on a little 250, and you are riding together she will have that thing strung out just to keep up, and that in and of itself makes the riding less enjoyable..
Just my experience, but she should get what she wants, and do the math and legwork to make sure she is prepared for riding it. Does she have any girlfriends who ride? My wife has a couple and that has made a huge difference, as she will go out with them and riding is now more than just "riding" it is also "girl-time".
Good luck!