Material to make underwear collected by girl after church (8)
I believe the answer is:
chambray
'material' is the definition.
(chambray is a kind of material)
'underwear collected by girl after church' is the wordplay.
'underwear' becomes 'bra' (I've seen this before).
'collected by' means one lot of letters goes inside another.
'girl' becomes 'amy' (**).
'after' is a charade indicator (letters next to each other).
'church' becomes 'ch' (common abbreviation).
'bra' going inside 'amy' is 'ambray'.
'ambray' after 'ch' is 'CHAMBRAY'.
'to make' acts as a link.
(Another definition for chambray that I've seen is " Mary Bach makes a lightweight woven fabric".)