I wouldn't waste another minute on them.
Call the court house and inform them of her refusal to do community service.
Call a locksmith and change all the keys.
Call them and tell them to f*** off.
It's a tough situation, but I agree with the poster who wrote that you should contact the court and keep both of them out of your life.
Since your son was the one who urged his wife to pawn your jewelry, I think he's as bad - or worse - as she is.
You apparently have other children.
Just try to see that they marry so you can see their children.
Don't blame everything on your daughter-in-law. Clearly your son is her enabler. The best thing you can do is try to remain a positive force in your grandson's life so that he has a good role model and won't grow up like his parents. On the other hand, you evidently didn't do such a great job instilling values in your son otherwide he wouldn't be with his horrible wife.
It takes two to bring up baby.
If this woman's son is no prize it may not be her fault.
Besides, with the best will in the world, it's just not possible to set some children straight.
There really is such a thing as a bad seed.