Quite, quite twee (6-6)
I believe the answer is:
pretty-pretty
'twee' is the definition.
(I've seen this before)
'quite quite' is the subsidiary indication.
'quite' becomes 'pretty' ('pretty' can be a synonym of 'quite').
'quite' becomes 'pretty' ('pretty' can be a synonym of 'quite').
'pretty'+'pretty'='prettypretty'
(Other definitions for pretty-pretty that I've seen before include "too cute" , "Twee" , "Knick-knack; over-dainty" .)