Guide daughter to wear a sun-blocker (7)
I believe the answer is:
advisor
'guide' is the definition.
(I've seen this before)
'daughter to wear a sun-blocker' is the wordplay.
'daughter' becomes 'd' (genealogical abbreviation).
'to wear' indicates putting letters inside (to wear something is to be covered up by it).
'sun blocker' becomes 'visor' (I've seen this in another clue).
'a'+'visor'='avisor'
'd' placed within 'avisor' is 'ADVISOR'.
(Other definitions for advisor that I've seen before include "one counsels" , "I recommend" , "One giving counsel (O, not E)" , "One offers recommendations" , "Assistant" .)