How to lose weight for runway modeling?

Patient: I’m 16 years old 5ft 9 and weigh 110 pounds. I need to lose inches around my legs, waist, and thighs. Yes I know I’m already very thin, and underweight, but I need to be able to fit into sample sizes. What exercises would work to make me smaller in these areas? I’ve tried squats but they made my thighs too bulky. Also what kind of a diet can help me lose weight safely? Yes I already know that I’m very thin but I would like to lose a little weight, and I need to get to a 23 inch waist and 33 inch hips. I have been this size before. I am currently in a size 3 dress size, so as you can see it would be a realistic goal for me. I know my goal may not be too healthy, but this is part of my career choice. How can I do this as healthily as possible?Thanks in advance!