self consious and family doesnt help

im a teenager (13), and im really self consious about my stomach. i used to be really healthy, and i still am, but i have this pouche that i can never unotice. my mom, sister, and i have been dress shopping and evrytime u find something i like, my mom always points out my stomach, and it makes me feel like a size 35 (no offebse to anyone, im just trying to get my point across) when i can fit into a size three, and i just dint know what to do anymore.. any thoughts?