Instead of simply telling your daughter that she's cherished and loved, why not show her?
If you have a camera, take turns photographing things around the house and outdoors that represent her one-of-a-kind traits. Perhaps an image of her tennis shoes could signify her athletic spirit, or a photo of a blooming flower might symbolize her beauty. Ask her to track down things that she appreciates the most about her family or friends as well.
To make a day of it, drive around town and take pictures of special landmarks or her favorite places. Daughters who like to draw or paint may prefer creating their own pictures. After you're done taking pictures or sketching, make an album or a handmade book for her to keep.