higher end used. Just make sure that you get it checked out thoroughly, and the seller will accept a return if it is found to not be in the described condition (like if the inspector/shop finds a blown seal or crack in the frame, etc).
She'll probably end up on a hard tail, unless she really wants FS, and is willing to go for a cheaper set-up to get it.
But you could have her "try on" new bikes, just to test the fit of the geometry. That way, she'll know what to look for. There are lots of used bikes and parts for sale on MTBR.com. Since you are in a good territory for mountain biking, you can also look into used rentals. That's how I got my first mountain bike. It may also help if she is willing to wait until Fall. Especially for used rentals, when they try to get rid of the fleet. Remember, she could rent a good quality bike quite a few times while she saves up more money and waits to find a good deal. Plus, rentals are a good demo source.