I agree with Bill Cody. Third fish looks female. Mouth / gape can very with Green Sunfish as a function of what the fish consumes as prey. Ewest can dig up peer reviewed paper to support that.
Care must be taken not to cherry pick fish for pictures. Overwhelming majority pictures of single sunfish I see posted appear to be male. We tend to use males more than females which can result in characterizing females being less reliable.
