How can i get a friend to stop being mad at me?

So my sister got my friends ipod touch and my sis erased all the games $40 worth i got her a 50 dollar gift card but she is still mad at me!!!!!!!!!!!!!!!! HELP!!!!!!!!!!!!! i have known her sense pre k and know im in 6th grade with her i love her to death in a friend way and dont want to loose her help