I am so sorry for your loss, you must both have been through a lot of grief,.How does your wife behave around your Daughter is she quiet, does she talk and play games withthe child, I can imagine it makes your wife sad but this could be remedied.,perhaps your wife could have some one to one time with her Grand daughter, when the Family is not there as maybe the 2 of them together would be less competition,there are a lot of Family around she needs some playing with just you both. How about your wife takes her to the Park or a play ground just the 2 of them, give her a lot of attention,