Sorry about your GF's grandmother... she must feel pretty bad right now. Anyways, you and your gf will forget about it in a matter of time... people just come and go.
I really feel for you man. It is a horrible feeling to loose someone close to you but im sure she would want you and your girlfriend to keep positive and build for the future
When someone dies it is always a reminder that we need to spend more time together with people who matter, be it family or friends, while they are still around. Life often gets busy and priorities messed up. Things like this always remind about what really matters in life. Our thoughts and prayers are with you, be there for each other.