She’s kept quiet (3)
I believe the answer is:
mum
'quiet' is the definition.
(thesaurus)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for mum that I've seen before include "Palindromic mater" , "Parent - shtoom" , "Mother (colloq.)" , "Informal palindromic mother" , "Silence" .)