Daughter in bad role eclipsed by mother in sensational performance (9)
I believe the answer is:
melodrama
'sensational performance' is the definition.
(I've seen this before)
'daughter in bad role eclipsed by mother' is the wordplay.
'daughter' becomes 'd' (genealogical abbreviation).
'in' means one lot of letters goes inside another.
'bad' indicates anagramming the letters.
'eclipsed by' means one lot of letters goes inside another.
'mother' becomes 'mama' (mama informally means mother).
'role' anagrammed gives 'elor'.
'd' put inside 'elor' is 'elodr'.
'elodr' inserted within 'mama' is 'MELODRAMA'.
'in' is the link.
(Other definitions for melodrama that I've seen before include "Extravagantly styled play" , "Histrionic behaviour" , "sensational affair" , "sensational performance" , "Histrionics - sensational play" .)