How many women are 4 star generals?

There are currently 40 active duty officers of 4 star rank (generals & admirals) in U.S. Forces. There appear to be well over 200 living retired 4 star generals.

14.

Currently? Five. James Cartwright, Vice Chairman, Joint Chiefs of Staff James Conway, Commandant of the Marine Corps James F. Amos, Assistant Commandant of the Marine Corps Robert Magnus,...

Yes. The highest rank in the Canadian Forces is a General, who is also the Chief of Defence Staff. He is equivalent to an American five-star General.

The Brigadier General is a "one star" general.