Stress over independent daughter's mishap (8)
I believe the answer is:
accident
'mishap' is the definition.
(thesaurus)
'stress over independent daughter's' is the wordplay.
'stress' becomes 'accent' ('accent' can be a synonym of 'stress').
'over' means one lot of letters goes inside another.
'independent' becomes 'i'.
'daughter' becomes 'd'.
'i'+'d'='id'
'accent' going around 'id' is 'ACCIDENT'.
(Other definitions for accident that I've seen before include "Prang" , "Mishap, misadventure" , "Collision" , "Dance tic leading to mishap" , "Eg, car crash" .)