Dotty over young woman (6)
I believe the answer is:
maiden
This clue is a double definition.
'dotty over' is the first definition.
(I've seen this before)
'young woman' is the second definition.
(maiden is a kind of young woman)
(Other definitions for maiden that I've seen before include "I named (anag) - young woman" , "No-score over" , "Girl; kind of over" , "Six dot balls" , "Unmated; runless over" .)