This is a very beautiful story. But the choice of the movie that she wanted to see makes that story even more touching. She could have chose to see any other movie (Star Trek, Toys Story etc etc). However, the main theme of UP is how someone can deal with the loss of a loved one and how he can pursue the dream of the loved person.
UP is a great movie with a lot of funny parts in it. I laughed several times. The animation is also excellent. However, for those of us who recently lost someone, that movie also has a very deap meaning and we can connect to the main character and his feelings throughout the movie.
I found UP to be funny and sad at the same time. After reading the story of that little girl, I will never be able to watch that movie the same way. The parents of this child will probably feel this too if they wish to see that movie again.