At 5'6", 160 is pretty heavy, even if she has a lot of muscle she is still going to be big. I don't mean fat I just mean wide hips big bones....big. My GF was a state champion sprinter so she has A LOT of muscle in her legs and a big round ass, she hits the gym 4-5 days a week doing full body workouts, she has very defined arms and a nice flat stomach. My point is she is very muscular and she is 5'5" 130, so if she was to get to 160 and it was muscle?!?!? HOLY SHIT, she'd be jacked....