七分淑女范三分流氓气

This describes a person with an overall elegant and ladylike demeanor (70% - '七分'), mixed with a hint (30% - '三分') of rogue or naughty behavior ('淑女范' means graceful like a lady, and '流氓气' indicates some roughness or rascality). It implies that despite outward poise, there’s still a rebellious streak.