She's crazy about the youth centre (4)
I believe the answer is:
maud
'she's' is the definition.
'crazy about the youth centre' is the wordplay.
'crazy' becomes 'mad' (synonyms).
'about' means one lot of letters goes inside another.
'the youth centre' becomes 'u' (middle letter of the word 'youth').
'mad' placed around 'u' is 'MAUD'.
(Other definitions for maud that I've seen before include "Come into the garden, - (Tennyson)" , "Tennyson poem" , "Old song: ''Come into the garden . . . .''" , "Girl invited into garden (Tennyson)" , "Girl invited into the garden in song" .)