You might want to consider getting her x-rayed. If her legs are bothering her at 2 from jumping then it might be something that needs further investigation. A 2 year old dog if they are sound of structure and at a proper weight should not be having leg problems from jumping.

Also depending on her height at the whithers she should only be jumping from 20-30 (that depends on what organization) dogs that are 18"-21" should only have to jump 20-22" which considering that she's 2 she should only just be starting at...after all dogs bones aren't fully developed until they are 18 months and shouldn't be jumping their full height until then. Jumping a dog at their full height before that age could really cause some problems.