I found something about the Sumerians here.
And Manu's laws concerning a woman's rights:
The Sumerians put the domination of men over women into law. If a husband died, the widow came under the control of her former husband's father or brother, or if she had a grown son she was put under his control. A woman in Sumer had no recourse or protection under the law.
1. I will now propound the eternal laws for a husband and his wife who keep to the path of duty, whether they be united or separated.- Manu Smriti, Chapter IX
2. Day and night woman must be kept in dependence by the males (of) their (families), and, if they attach themselves to sensual enjoyments, they must be kept under one's control.
3. Her father protects (her) in childhood, her husband protects (her) in youth, and her sons protect (her) in old age; a woman is never fit for independence
The similarities between Sumerian laws and Manu's laws can be put down to Haplogroup J2a and G2 migration into India. However, considering that they appear bit late in the Vedic literature the West Asian region must have become Semitic who identified some of their thoughts in Sumerian culture.