D.S.
Well, at least you are raising a child who has deep emotional capacity and empathy for living (and stuffed) things, that's a good thing right!! :)
My son can be like that when he is not winning at games. At first I would do some comforting and talking/explaining because I do think a mom's job is to coach a child through life's emotions, but now that I know he has the basic understanding I just let him go off and pout alone. I think it's important for your daughter to feel the natural consquence of her actions (which is that the game goes on without her and she might end up feeling left out). This is what would happen in the real world, in a playgroup or on a playground. Of course I would follow up and talk about it later like when I am putting her to bed or driving her home. But it's important to impart the skills for her to get through it at that moment on her own. It's hard to see her sad and hurt, I am sure, but you'd be a better mom for teaching her to manage these experiences then if you protected her from them. It's a skill she really needs. Good luck.