Women's light suit jacket

Cos Cob. vintage suit jacket in an off white shade, no size label but measurements are shoulder to shoulder 19",pit to pit 18"buttoned waist 18", sleeve cuffs 12.5"completely around, Google suggested this is compared to a medium size, pre owned in excellent condition, I recommend measuring these measurements with your own jacketanother jacket to compare jacket size with one you own this jacket already at the . lowest discount price