Hi there. Thanks for the question. Let me see if I can help.
Constant or obsessive licking can be a sign of pain or anxiety.
Is she eating normally? Is she otherwise acting normal or is she showing any other signs of pain?
Pain in the hind quarters (perhaps hips) or back could cause her to not want to jump on things and the licking would be her sign of pain and distress over the pain
If she seems to not be as eager of an eater right now....or is intermittently vomiting or having loose stools....then maybe she has a mild pancreatitis and is licking because of the abdominal pain and may not want to jump up because it stretches the abdomen and hurts.
These are just some thoughts. A vet exam would likely provide a lot of insight (especially on the pain side of things)
I hope this has been helpful. Let me know if you have any questions.