Maybe in the video, G'ma can reference JW.org, and how glad she was to see under FAQ "Do You Shun Former Members of Your Religion?" that the JWs don't shun family members and that as long as there is no religious ties the normal family affections and dealings continue.
"What of a man who is disfellowshipped but whose wife and children are still Jehovah’s Witnesses? The religious ties he had with his family change, but blood ties remain. The marriage relationship and normal family affections and dealings continue."
Maybe this will spark something in your daughter...maybe it will cause her to at least notice how deceiving the WT is to public about their shunning policy. The site doesn't mention as they have in the recent conventions that this only applies to persons living within the same household.
So G'ma being away from the JW for so long could be very delighted in the answers on JW.org...that may open a door for your daughter to at least clarify her current behavior to grandma.