Rodeo hat redesigned for girl (8)
I believe the answer is:
dorothea
'girl' is the definition.
'rodeo hat redesigned' is the wordplay.
'redesigned' indicates an anagram.
'rodeo'+'hat'='rodeohat'
'rodeohat' anagrammed gives 'DOROTHEA'.
'for' acts as a link.
(Other definitions for dorothea that I've seen before include "Mrs Casaubon" , "gift from God" , "Girl" , "Woman" .)