In time, is girl a soft thing to be discarded? (6)
I believe the answer is:
tissue
'a soft thing to be discarded?' is the definition.
(tissues get discarded)
'in time is girl' is the wordplay.
'in time' becomes 't' (abbreviation. I am not sure about the 'in' bit.).
'girl' becomes 'Sue' (girl's name).
't'+'is'+'sue'='TISSUE'
(Other definitions for tissue that I've seen before include "Paper hanky" , "series of lies" , "Thin stuff" , "Flimsy paper" , "cell block?" .)