"He's trying to sell a phony pearl," the daughter put in (6)
I believe the answer is:
pedlar
'he's trying to sell a phony' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'pearl the daughter put in' is the wordplay.
I cannot really understand how this works, but
'daughter' could be 'd' (genealogical abbreviation) and 'd' is found within the answer.
an anagram of 'pearl' is 'pelar' which is within the left over letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for pedlar that I've seen before include "dealer?" , "Travelling vendor of small goods" , "Mobile salesman" , "Itinerant seller" , "Itinerant vendor" .)