Also depends on her build, if she is bigger boned, she will weigh more, if just tall and lightly build, she will weigh less. My OJ was 18 1/2 and at good show weight was 28lbs, regular weight, 25lbs… and he was bigger boned.
Bitches typically even if tall or big should still be less then males. But you really need to look at the dog, not the scale. You should be able to see a "waist" if looking down at her.. she should have a "tuck-up" from from the rib cage through the loins (underline). You should be able to feel the ribs lightly under the coat and you should see a "hint" of rib outline when they are gaiting.