Hawks have (or had - the SV650 may have taken a bite out of the Hawk scene, I don't really know) a cult following. I've heard their reliability is typical Honda. I'd expect them to be fine at 70mph. The only way to be sure about the bars is to have her sit on one, but I doubt they'd be a problem.
Here's a web site to do some more research:
http://www.hawkgt.com/
I've given you a lot of speculation, but if it fits her and she likes it, I really think this could be just what you want.