Honestly, I wouldn't go, except if I felt personally obligated to go. Funerals are really a ritualistic sort of thing when you think about it, and depending on your personal belief system, either they will be really important, or they won't be important at all. I don't see the point of them myself, and I actually don't want to have a funeral. I'm OK with people mourning my demise in their own homes when I pass, but I don't want to make a big fuss about it. Living things die, and I'm just another living thing.
So, you have to ask yourself, is going to your grandmother's funeral worth the suffering you'd feel? You may face disapproval from other people if you decide not to go, but it's not like you're morally obligated to, in my opinion. The last time I attended a funeral was over 10 years ago, and a number of people I've known in my life have died between then and now.
Death is a tragic thing, but it's something that happens to all of us eventually. instead of thinking about your grandmother's death, think about the life she lead, and all the things that made her a good person. 
It's really up to you; go, or don't go.
I know my opinion on the matter will likely be unpopular, but the fact remains that as a non-religious person, I just don't attend funerals, nor do I expect to have a funeral for myself. I've been dragged to a few weddings, but they're so overly glamorized and stuff that people don't understand why I wouldn't want to attend them. They're just like really lame parties, if you ask me.
Last edited by mr_bigmouth_502 on 25 Feb 2015, 2:25 am, edited 1 time in total.