Most Helpful Guy
Something I did was to create an email account and I kept sending emails to it, addressed to her. I sent pics, videos etc, and basically preserved our memories by uploading it on the internet. On her birthday, I gifted her the email Id and the password. You can only imagine the smile on a girl's face when she relives those beautiful memories through your words. :-)
Most Helpful Girl
I don't know why but the first idea that came to me when I read this was seashells. if there's a beach around you, you can find some and try to make a cute present for her. could be a necklace or smt and you can make up a story about that seashell, just to make it more dramatic.