When the movie starts, it is said that Helene is 75 years old. The Los Angeles retrospective is also mentioned as an event to happen soon after that first reunion, and given that Helene dies little time after that, we can perfectly assume that she was 76 at most when she passed away. Yet, near the end of the film, a shot of her grave denotes that she was born circa 1912, and that she died in 2007. That would make her around 95 at the time of her death.
When the grandmother is opening the gifts in the first scene, she tears all the paper off of the book then when the camera angle switches, she pulls off some more wrapping paper, then in the third shot, the book is still partially covered in wrapping paper.