No, but her 'estate' will get a lawyer to represent the dog's rights...

Thing is, her grandchildren could contest it, but if it was in her will and she was sound of mind? She pretty much had the right to leave her money to anyone or anything she wished to leave that money to...And the courts will more then likely, will not go against her will anyways.

What she did really isn't that unusual, happens every day in fact...People just don't hear about it unless it's a substancial estate being left to the family pet or some 'charity'.