Your writer grumbles about girl (5)
I believe the answer is:
naomi
'girl' is the definition.
(girl's name)
'your writer grumbles about' is the wordplay.
I cannot really see how this works, but
'writer' could be 'i' (the person who is writing these clues) and 'i' is found in the answer.
'about' could be 'a' (abbreviation in Chambers) and 'a' is located in the answer.
The remaining letters 'nom' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for naomi that I've seen before include "woman in the Bible" , "Biblical woman" , "Mother-in-law of Ruth (Bible)" , "Biblical character" , "mother- in-law" .)