For me, Jane Fonda gives the film's liveliest performance. Liberated from the lacquered, overly-mature look adopted for The Chapman Report and Period of Adjustment (both 1962), Fonda is sexier and looser here. Perhaps a little too loose in her early scenes. There's something about "earthy" that brings forth the inner ham in actors. Fonda in her early scenes can't seem to keep her finishing school refinement from creeping into her overly-mannered interpretation of Kitty Twist, railway ragamuffin.
Parts of her performance have the feel of an over-coached acting school scene. But, unlike so me of her co stars, she's never a dull presence and really comes into her own in the sequences in the Doll House. She looks amazing as well. The cameraman obviously thought so too, for Fonda's shapely backside has arguably as many closeups as her face.