I am really sorry to hear what happened. I know how it feels not to attend one of your grand-parents funeral. 2 years ago, me and my mom decided to go to Iran for the summertime to visit my grand-father (her father) because he was really sick (he had diabetes). This would be me first time going there and this would be for my mom her first time after 23 years that she left Iran. She and my grand-father planned everything that was going to happen. They would go visit their chalet, their old farm , going to see some old friends etc... But on his birthday (13th febuary), he died (he turned 68). My mom called him to wish him happy birhtday, but my mom's uncle picked up the phone and he didnt pass the phone to him (he was dead by that time) and my mom understood. We couldnt make it to the funerals, every one was like we understand. They said that anyways, you are going to visit his grave during the summer time. We did, but we felt ashamed that we didnt attend his funeral.

Also, my mom's aunt died at the end of March and beggining of April, but none of our family member told us. They said that bad news shouldnt come to us . Finally a friend of the family member called us to say sorry for what happened. We finally understood that she died. It was worst that they telling us. At least, your family called you to tell you that she died.

Dont forget, your grand-mother does not want her death to ruin your vacation.