First, you can get the origin of it from the dictionary on this site by clicking on the linked name:
Lacey
Lacey was first used enough for girls to make the top 1000 list in the USA in 1975. Its highest rank was #116 in 1984, but if you added in alternative spellings such as Lacie,
Laci, and
Lacy it would have been higher than that.
What other sort of information do you want to know? Your request is rather vague. :)