But you don't NEED it to be. I honestly think it'll be better if you find someone else to discuss it with (one of the reasons being what you pointed out about keeping your mouth shut about the separation). Do you have other family members you can talk to?
I'm sorry for your Mawmaw, Heim. I've lost all of my relatives over the last 7 yrs, and I strongly agree with OT -- go see her.