sounds like a lovely idea - but ultimately, you know your friend more than we do. what i think is a lovely gesture, your friend may think is silly kwim? go with your heart, your gut, and your knowledge of your friend. you can't go wrong if you do that hun.

she obviously knows you (because i would not consider concert tix for someone who had just lost their angel - except for one or two friends) - and she chose well - trust yourself to do the same