Body Weight for Women

Ideal Weight For My Body Type? (thoughtful Answers Much Appreciated)?

I have been dieting since January, following the Weight Watchers points system and losing about 1.5-2 lbs/week. I’ve also been doing lots of exercise – 30 min. on the treadmill, 30 min. yoga, lots of walking everyday. I’ve lost ~21 pounds so far and am now at 180 lbs. I need help figuring out what would be a good healthy weight for my (hour-glass) figure and (large) body frame (my wrist is ~6.5 inches).
My measurements are currently:
Bust – 39 inches (I wear a 38 DD and have always been full-figured)
Waist (inch above my belly button) – 30.5 inches
Hips (at their widest) – 38.5 inches
Shoulders (at their widest) – 42 inches
I usually wear medium or large-size shirts; I’m fitting comfortably into my size 10 (Old Navy) jeans again.
I was thinking of losing 20-30 lbs more max, for a final weight of 150 or 160 lbs. What do you all think?
I am 5″3. I am frustrated w/ internet weight charts saying someone my height should be 100 lbs – so unrealistic for my body type.