Not paired off, daughters need love first of all (3)
I believe the answer is:
odd
'not paired off' is the definition.
(as in odd socks)
'daughters need love first of all' is the wordplay.
I cannot really understand how this works, but
'daughters' could be 'dd' (a genealogical abbreviation for daughter repeated) and 'dd' is located in the answer.
'love' could be 'o' (love means zero in tennis) and 'o' is found in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for odd that I've seen before include "One is" , "Unusual, strange" , "Peculiar in uneven way" , "Rum" , "Queer" .)