There are a few options and it depends on if you are using it for support or safety. If she will be playing a sport and wants to keep it from getting bruised then I would suggest she try the
IMPACT OS Pad - Osgood-Schlatter's Premium Pad:
https://www.ithacasports.com/ospad.html.
If she just needs some minimal support then she can take a look at the different compression sleeves available here:
https://www.ithacasports.com/compression-knee-sleeves.html.
Please let us know if you need any help in choosing. We have a Certified Athletic Trainer on staff.