Daughter and I emphasise pain (8)
I believe the answer is:
'pain' is the definition.
(I know that distress is a type of pain)
'daughter and i emphasise' is the wordplay.
'daughter' becomes 'd' (genealogical abbreviation).
'and' means one lot of letters go next to another.
'emphasise' becomes 'stress' (synonyms).
(Other definitions for distress that I've seen before include "Deep anxiety" , "Extreme pain, poverty" , "Extreme anxiety or pain" , "Extreme sorrow or pain" , "Suffering, worry" .)