What were Wu Zetian’s actual achievements and what did she do to her family?

Eman, she chose capable men to be officials. She held competitions to select military officers. She attached great importance to agriculture development. During her reign, social economy develeped fast. It's she who laid the fundation for the heyday during the reign of Emperpor Li Longji.

She was cruel to her families. It's said that she killed 10 of her close familes and relatives. She had four sons and two daughters. Her first daugther was dead very young. She had three of her sons exiled or deposed. Because her little son was willing to be controlled by her, she didn't make him suffer like his brothers.