Has your therapist given you any advice on how to minimize the emotional damage this mess may cause your daughter? If this lasts until Christmas, is she old enough to understand why you're not celebrating with gramma this year? I don't have any kids, so when my mother and I are at odds it doesn't really affect anyone else, but if I had young children I think it would be hard for me to explain all this to them. If your daughter is close with her grandmother what will you tell her when she says she wants to go visit grandma?
And while we're talking about your kid, how has she been doing since losing her grandfather? Did you take her to the funeral?