I had speculated that Dee found the locket on Earth, but upon reviewing it, that doesn't appear to be the case.
It looks more like she found a watch and a set of jacks (including a rather improbably preserved 2000-year-old ball) and this added to her planetary depression, and that she looked at a locket with pictures of her ?parents? at the end.
Unless there is a major continuity issue, the watch she finds at the beginning is clearly much bigger than the locket at the end.
jacks with ball (ball highlighted with red box)