That woman's taking in newspaper that is more powerful (7)
I believe the answer is:
heftier
'more powerful' is the definition.
('hefty' can be a synonym of 'powerful')
'that woman's taking in newspaper that is' is the wordplay.
'that woman's' becomes 'her' (I've seen this before).
'taking in' is an insertion indicator.
'newspaper' becomes 'ft'.
'that is' becomes 'ie' ('i.e.' can be a synonym of 'that is').
'ft'+'ie'='ftie'
'her' placed around 'ftie' is 'HEFTIER'.
(Other definitions for heftier that I've seen before include "Bigger" , "More weighty" , "more vigorous" .)