First Lady's not without love? It happens (5)
I believe the answer is:
event
'it happens' is the definition.
(I've seen this before)
'first lady's not without love?' is the wordplay.
'first' means one lot of letters go next to another.
'lady' becomes 'eve' (I've seen this before).
'without' suggests deleting specific letters.
'love?' becomes 'o' (love means zero in tennis).
'not' with 'o' taken away is 'nt'.
'eve' next to 'nt' is 'EVENT'.
(Other definitions for event that I've seen before include "riding competition" , "Incident - final outcome" , "one item in programme" , "Incident, occurrence" , "Anything which happens" .)