Woman in control shows strength (9)
I believe the answer is:
hardiness
'strength' is the definition.
(I know that hardiness is a type of strength)
'woman in control' is the wordplay.
'woman' becomes 'Di' (short for Diana).
'in' indicates putting letters inside.
'control' becomes 'harness' (harnessing is a kind of controlling).
'di' going inside 'harness' is 'HARDINESS'.
'shows' acts as a link.
(Other definitions for hardiness that I've seen before include "Courage" , "Fortitude" , "Resilience" .)