After a time children’s author becoming vulgar (6)
I believe the answer is:
tawdry
'vulgar' is the definition.
(synonyms)
'after a time children's author' is the wordplay.
'after' is a charade indicator (letters next to each other).
'a time children' becomes 't' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'author' becomes 'awdry' (I've seen this before).
't'+'awdry' is 'TAWDRY'.
'becoming' is the link.
Can you help me to learn more?
(Other definitions for tawdry that I've seen before include "Cheap and flashy" , "Gaudy but valueless (6)" , "Showy but cheap and nasty" , "Tastelessly showy" , "Cheap; sleazy" .)