In a formal letter to the mayor, Sandi Jackson on Friday afternoon resigned as Chicago's 7th Ward alderman.
She said her decision to resign, effective Jan. 15, was made with a "heavy heart."
"As a representative of the people of the 7th Ward, I value the public trust which has been bestowed upon me and take my responsibility to safeguard the interests of my constituents seriously," she said in her resignation letter.
"Likewise, I am unapologetically a wife and a mother and I cannot deny my commitment to those most important personal responsibilities," she continued. "To that end, after much consideration and while dealing with very painful family health matters I have met with my family and determined that the constituents of the 7th Ward, as well as you Mr. Mayor, and my colleagues in the City Council deserve a partner who can commit all of their energies to the business of the people."
In a statement, Mayor Rahm Emanuel said Jackson's "leadership has been greatly appreciated."
"As Sandi takes this time to focus on her family, we give her out deepest thanks and support for her service to our city and the residents of her ward," he said.
Her resignation comes a little less than two months after her husband, Jesse Jackson, resigned as Illinois' 2nd District congressman amid a federal probe and after months away from his congressional duties with a diagnosis of bipolar depression.
Soon after her husband stepped down, rumors swirled that she was interested in running for the Congressional post.
"I will finish my term. I intend to finish my term," she said in December, denying the rumors. "Unless something catastrophic happens -- I could step outside and get hit by a bus today."
Federal authorities had been looking into whether the former congressman used campaign funds to decorate the couple's Washington, D.C. home. The couple briefly put the home on the market.
Additionally, Sandi Jackson had recently been asked by Illinois' State Board of Elections to explain a $69,000 discrepancy between her campaign finance reports and those of her husband.
No charges have been filed against either Jackson.
Also on NBCChicago.com: 22 candidates file for Jesse Jackson Jr.'s vacated seat
Her predecessor in the 7th Ward, Bill Beavers, said he wasn't shocked by the news.
"Not surprised. She was never there," he said, referring to the D.C. home.
Beavers is now a Cook County Commissioner. He's also feeling the heat of the feds, accused of taking thousands of dollars in campaign dollars for personal use. He's pleaded not guilty and maintains prosecutors are after him only because he refused to wear a wire on fellow Commissioner John Daley.
Emanuel said the process to find a replacement for Jackson, who was elected to the Chicago City Council nearly six years ago, will begin next week. The post will be filled through a mayoral appointment and would be Emanuel's first.
A special primary to replace the former congressman will be held on Feb. 26 with the General Election following on April 9.