By marrying, she has defeated another stigma against rape victims in conservative Pakistani society.
the facts in further paragraphs of the article indicate she has been manipulated into the marriage:
Mr. Gabol had a hard time persuading Ms. Mukhtar to marry. He had been calling her off and on since 2003 but formally proposed a year and a half ago, she said. “But I told my parents I don’t want to get married.”
Finally, four months ago, he tried to kill himself by taking sleeping pills. “The morning after he attempted suicide, his wife and parents met my parents but I still refused,” Ms. Mukhtar said.
Mr. Gabol then threatened to divorce his first wife, Shumaila.
Ms. Shumaila, along with Mr. Gabol’s parents and sisters, tried to talk Ms. Mukhtar into marrying him, taking on the status of second wife. In Pakistan, a man can legally have up to four wives.
It was her concern about Ms. Shumaila, Ms. Mukhtar said, that moved her to relent.
“I am a woman and can understand the pain and difficulties faced by another woman,” Ms. Mukhtar said. “She is a good woman.”
In the end, Ms. Mukhtar put a few conditions on Mr. Gabol. He had to transfer the ownership of his ancestral house to his first wife, agree to give her a plot of land and a monthly stipend of roughly $125.
Asked if she had plans to leave her village to live with her husband in his village, Ms. Mukhtar said no. “I have seen pain and happiness in Meerwala. I cannot think of leaving this place.”
Her husband, she said, “can come here whenever he wants and finds it convenient.”
Remember that in Islam, the man can divorce his wife at any time by merely saying "I divorce you" three times. He is only obligated to provide her with financial support for six months after the divorce. So, Mukhtaran Bibi has taken pity on the first wife of the constable and negotiated for her financial security. But also remember that Islam requires a wife to submit to her husband's sexual desires at any time. So Mukhtaran Bibi ensured the man's first wife financial security, but only by agreeing to be the man's wife, ie, subject to the sexual desires of this man whenever he wishes. Seems like she has been manipulated into being a rape victim for the rest of her life.