Official concerned with overseeing First Lady (5)
I believe the answer is:
reeve
'official' is the definition.
(I know that reeve is a type of official)
'concerned with overseeing first lady' is the wordplay.
'concerned with' becomes 're' (re can mean regarding or about).
'overseeing' says to put letters next to each other (in a down clue, some letters go over others).
'first lady' becomes 'eve' (Biblical first woman).
're'+'eve'='REEVE'
(Other definitions for reeve that I've seen before include "Pass the end of a rope through the bailiff" , "Anglo-Saxon magistrate - female bird - pass (a rope) through a hole" , "thread his way through" , "Female ruff; also a bailiff" , "Pass a rope through a ring" .)