My second bike was an 03 xb9s. In my opinion, the bike matters less than the mental maturity of rider. If she fits on the bike and is comfortable with the ergonomics that will make for a more enjoyable experience than buying a bike based just on engine size/power delivery. The more she enjoys the bike the more likely she'll be to get on it, ride, and build her skills.
That being said, keep in mind laying an XB over can result in more damage that may not be easily repaired. If you're concerned about rider skill, you may want to consider a bike that's easier to find parts for incase it gets dropped a couple times.