The Queen (2006) Helen Mirren > crying scene... Deep insight needed?

I think that the sheer beauty and innocence of the animal touched her so that all of the feelings about what has been happening just overwhelm her and she 'breaks down' so to speak. She has been 'keeping a stiff upper lip' through the whole thing because of her position, and her humanness overtakes her and she let's out some bottled up feelings. A venting... or purging, if you will.