I think most girls have their favorite simple "Carrie"-type necklace. Mine is a little silver chain with two tiny charms - one a bee and the other a cute little shoe from Holland my aunt brought back for me when I was a young girl. My mom recently gave me a new pendant that she made from an old, pretty dime I found one time when I was home that I had forgotten about. An appreciation for old, antiquey things is ingrained in me - coins, books, heirlooms, etc. I especially like the older coins for this because they usually have higher precious metal content (this old dime is 90% silver) and the romantic in me likes the little piece of history around my neck. Just think about all the things a 1944 dime could have seen or all of the people who may have once held that same coin. Making a pendant with a lucky penny or coin from your birth-year, anniversary, or any other special year is a fun application too. It's easy to make one yourself, just search for "screw top bezel" and keep your eye out for special coins!
When Bea is up on her tall changing table she holds my necklace and finds the bee charm. She always makes sure to point it out. I tell her that it's my special Bea charm so that she is always with me even when we each go to school during the day. She gives me a big smile. One day she'll get a little necklace too.