That's Moon Maid. She was the daughter of the ruler of the Moon and helped Tracy out. Dick Tracy was, at one point, out of crimes to solve and crooks to kill on Earth that he found himself on the moon looking for business in the 60's. Basically she was the result of a prohibition era comic trying to stay relevant during days of the Space Race.
Moon Maid's fate was sealed when she was on the wrong side of modern sensibilities. She died when a car rigged for Dick Tracy exploded and then was never mentioned ever again.