Originally Posted by omak

I have been thinking and went back to the original start of this thread to see if my responses have been directly in line with what Pam was asking.
Having read it again, I saw something else that I had not considered.
If you don't step in to defend the 3yo, you are teaching him that he is not worth as much as the baby ... so that would be a very good reason to intervene. You can counsel daughter as you have, and, I think you should - - if she doesn't want to hear it, she won't be coming around.
I was noticing the laptop story, and I thought - - why would grandma allow a baby to threaten her in any way, shape, or form.
I know that you maintained control of the mouse because you were bigger and stronger than the baby was, but he is growing - - and you aren't. One of these days, he will be able to wrestle the mouse away from you, and when he decides to hit you, it will be your fault that you got hit because if you had just given it to him in the first place, he wouldn't have had to hit you (the reasoning of a bully and abuser).
My father told me (while we working animals) what is cute when they are babies, isn't cute when they are 1200 pounds, and you have to always train with the final size and product in mind. (The same is true of humans - - I have probably stressed this before ...)
Grabbing YOUR mouse is rude - - and, you have the right to keep your own property and no one has the right to take it from you ...
You need to be secure enough in your own personage that you can tell your daughter, "Honey, I love you, and I love the kids, but as human beings, that littlest one is not very likable ... we need to find a way to train him so that others will enjoy being around him. No matter the age, there is no excuse for bad behavior." <wave>