Girl, on reflection, regretted one-woman shows (6)
I believe the answer is:
odette
'girl' is the definition.
(girl's name)
'reflection regretted one-woman shows' is the wordplay.
'reflection' says the letters should be written backwards.
'shows' indicates the answer is hidden within the clue.
'ettedo' is hidden within 'regretted one woman'.
'ettedo' back-to-front is 'ODETTE'.
'on' is the link.
(Other definitions for odette that I've seen before include "Female character Swan Lake" , "1950 film about first female to receive George Cross" , "Lover of Swann" , "Swan Lake role" , "------ Churchill, French war heroine" .)