I bought a charm and necklace on Amazon or Ebay for each of my daughters before we left for our trip several years ago. It was a Cinderella carriage charm and the pearl fit perfectly inside. It was a lot cheaper than the options at Epcot and it was cute!
I did the same as pp, but I got mine on etsy. It was so much cheaper and is adorable! We've done this every year for the last 4 and between my daughter and I we don't have 2 that are similar enough for earrings, which was my original goal. lol