Writer for example visiting little sibling in film (8)
I believe the answer is:
essayist
'writer' is the definition.
(essayist is a kind of writer)
'for example visiting little sibling in film' is the wordplay.
'for example' becomes 'say' ('say' can be used to introduce an example).
'visiting' is an insertion indicator.
'little sibling' becomes 'sis' (short for sister).
'in' indicates putting letters inside.
'film' becomes 'ET' (E.T. the Extra-Terrestrial).
'say' put into 'sis' is 'ssayis'.
'ssayis' going within 'et' is 'ESSAYIST'.
(Other definitions for essayist that I've seen before include "Bacon maybe" , "Writer of short compositions" , "kind of writer" , "The venturer" , "Writer of shorter pieces" .)