That lady would charge a large amount (8)
I believe the answer is:
shedload
'a large amount' is the definition.
'that lady would charge' is the wordplay.
'that lady' becomes 'she' ('she' refers to a woman).
'would' becomes 'd' (as in 'we'd' - 'we would').
'charge' becomes 'load' (loading is a kind of charging).
'she'+'d'+'load'='SHEDLOAD'
(Other definitions for shedload that I've seen before include "Myriad" , "great amount" , "a lot of it" , "big amount" , "A large number" .)