As far as bows, no bow I know of offers the performance and adjust ability as a kid grows like the Diamond Infinite Edge.

It will grow with her and she will be shooting targets and killing deer for years to come with it. It is top notch quality too.

http://www.diamondarchery.com/#/productBreakdown?r=products_products&i=42

As far as Crossbows, I shoot an Excalibur and love it. Wicked Ridge/Ten Point are also very nice if you want to go the compound crossbow route. The Warrior is a nice model. For the entry level hunter though, I would go with this one. She will be shooting bulls eyes from 20 to 40 yards in no time with it.

http://www.excaliburcrossbow.com/catalog/crossbow/axiom_crossbow_kit

Not a lot of used ones out there. Most people love their Excaliburs so much they don't want to part with them.