If your 5'6 female 161 pounds and 18 are you considered overweight?

Yes you are. I'm in the Marine Corps and our Max weight is 155. For an average everyday girl anything above 155 is overweight. But you're still young, just watch what you eat, excercise, and it'll go away. I was 170 when I was 18, and I'm also 5'6. But when I joined the Marines I got the weight off fast. Good luck with everything.