You can't go by size/weight.
Take your clothes off and look in the mirror, be honest about how much/where your body fat is and then decide if you want to change your body.
My youngest DD is a size 14, in jeans because of big hip bones, she's 5' 5" and isn't carrying excess body fat, she weight trains. My middle DD who also weight trains, is a size 6/8, but a 12 in a jacket because of wide shoulders and big boobs.