Our adopted son's birth grandmother wants to leave him a portion of her life insurance plan. They are asking for SS# and address. What should we do?

We have an adopted son that we have had in our care since birth. His parents, unfortunately, were/are not fit to care for him, and no one within his birth family was able to adopt him. We have cause to believe that, at this time, it's best to keep a bit of distance from the family. We send pics, but they are not current, and we are very protective of our location. That being said, there are certain people in his birth family that we believe, to the best of our knowledge, are wonderful people. His maternal grandmother is one of them. She is wanting to leave our son 25% of the money from her life insurance policy. Honestly, we think that's wonderful as well. However, our case worker (he was our foster child initially) called and asked if it was ok to fill out paperwork for the inheritance with our current address and his SS#. Is this safe? We do not, under any circumstances, want his family to know our location. Both the birth mother and father are unstable. Please advise.