"Black Beauty" author Sewell (4)
I believe the answer is:
anna
'black beauty author sewell' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for anna that I've seen before include "and eleven, twenty four across heroine" , "She's a woman, whichever way you look at it" , "Former Indian coin; girl's name" , "___ Pavlova, Russian dancer, d. 1931" , "Palindromic girl's name" .)