What is an ideal weight for a big boned female , 5 ft 11 ?

165 - 180 pounds: Decades ago, when I was in Medical School, ideal weight was estimated like this for women: 100 pounds for 5 feet tall; add 5 pounds per inch. So for 5'11", 160 pounds. But we do add some for bone structure: "big bones" I suppose 10-20 pounds would be fair. Other factors include genetics, muscularity, etc. Many think a better measure is body fat: ideal 22-25% probably. Google "measuring body fat"

No such thing: The "ideal weight" charts were put together decades ago by non-physician bean counters who looked at longevity without any common-sense about causation. Now sprinters tend to be "underweight" and linebackers "overweight". It's stupid. Your ideal weight is whatever looks and feels right to you while you are able to keep up in the sport(s) of your choice. Ignore everything else and stay fit.