I can completely sympathize with you, I also never was able to have my own human children so my 4 Bernese Mountain Dogs are my world. I'll say a little prayer for you and your family now. May God comfort you all.

try not to be confrontational with the daughter in law. Regardless of her conversation or opinions just try your hardest to get along with her. I know it's hard but for your son and grand children's sake it is required of you as the eldest to show your strength and your ability to control your own temper. I have prayed for your situation and hope that you can resolve this issue soon. May God bless.