I have always loved both Lucy and Sophie.
Lucy is my angel baby, and Sophie was on my short list for DC3.
Samuel is the name I would have given DD if she'd been a boy!
I don't know many little Lucy's at the moment. The two I do know are both spelt Lucie which may be becoming more popular?
Lucy is a name that never seems to age or date though.
That said I don't know many little Sophie's at the moment either.
Sophia/ Sofia seems to be more popular in our area.
I don't think you need to worry about popularity.