Willing to support a student so soon (7)
I believe the answer is:
already
'so soon' is the definition.
(I've seen this before)
'willing to support a student' is the wordplay.
'willing' becomes 'ready' ('ready' is associated in meaning with 'willing'**).
'to support' is a charade indicator (letters next to each other) (in a down clue, some letters hold others up).
'student' becomes 'l' (as in L-plates for learner drivers).
'a'+'l'='al'
'ready' after 'al' is 'ALREADY'.
(Other definitions for already that I've seen before include "earlier than might have been expected" , "Indication of impatience (US)" , "Even this soon" , "By the time in question" , "thus far" .)