In 2019, a story about gender discrimination centering on a presidential candidate was making the rounds, and a New York City progressive activist, Sasha Neha Ahuja, found it to be credible.

The candidate was Andrew Yang, and Kimberly Watkins, one of his former employees at the test-prep company he once ran, had publicly accused Mr. Yang of firing her after she got married, allegedly because he thought she would not want to work as hard.

“Wish I could say it was unbelievable,” Ms. Ahuja wrote on Twitter, sharing an article from HuffPost about Ms. Watkins’s allegations, which Mr. Yang has long denied.

Last month, Mr. Yang named Ms. Ahuja as the co-manager of his campaign for New York City mayor, selecting an operative who may be able to help him connect with progressives skeptical of Mr. Yang’s campaign. Yet a review of her activity on Twitter suggests that on multiple issues, involving politics and personnel, her instincts have been at odds with the leading candidate she is now assisting.

Her elevation to the role, running the campaign alongside Chris Coffey, a Tusk Strategies executive, came as a result of an apparent leadership shake-up within the campaign in the weeks leading up to Mr. Yang’s entry into the race.

The developments offer among the clearest signs yet of some of the turbulence that Mr. Yang, a leading mayoral candidate but a newcomer to city politics, has encountered as he works to get his campaign off the ground.

Ms. Ahuja said in a statement released on Friday that “when I heard the testimony in 2019, I was taken aback. It’s incredibly important for us to listen to the experiences of all people in the workplace, especially those who tend to experience discrimination most frequently.”

“It is also important to make sure all sides are heard and promote a workplace culture that is inclusive and committed to equity,” said Ms. Ahuja, who is the current chair of New York City’s Equal Employment Practices Commission. “That’s why when I had the chance to work for Andrew and build that type of culture on a mayoral campaign, I jumped at the chance and am so excited to be here.”

Her tweets also suggest that she has been far more progressive on matters including criminal justice than Mr. Yang is in his current bid. And during a recent special City Council election in Queens, Ms. Ahuja tweeted encouragingly about a deeply progressive candidate who was embraced by leading liberal figures but was vigorously opposed by some members of the Orthodox Jewish community, a constituency Mr. Yang is now aggressively courting.

Mr. Yang did not engage in that election, his campaign said, and Ms. Ahuja noted that “there are so few South Asian women who run for office in New York City and I support many of them, independent from any professional work.”

In a statement, Mr. Yang defended Ms. Ahuja’s tweets about him.

“The rest of the field can focus on my staffer’s tweets from years ago, but we’re focused on the big ideas like cash relief,” responding to Covid-19 and managing the economic recovery, he said. “I wanted my team to represent a diverse array of backgrounds, experiences, and views, and I’m proud to have all these folks fighting with me for New Yorkers.”

Ms. Watkins, who is now running for Manhattan borough president, said she was “shocked” after being shown Ms. Ahuja’s tweet on Friday.

“If she’s working now for Andrew Yang, having declared that she believed that to be true, it tells me that she is under the influence of someone who does not tell the truth about their history with women in the workplace,” Ms. Watkins added.

Ms. Ahuja’s appointment was not the only personnel change on Mr. Yang’s campaign team in recent weeks.

Zach Graumann, who was Mr. Yang’s presidential campaign manager, signed multiple fund-raising emails last month indicating that he was Mr. Yang’s mayoral campaign manager. Mr. Graumann, who came under scrutiny in a recent Business Insider article about how Mr. Yang’s 2020 campaign was mired in “bro culture,” is now listed as a senior adviser to Mr. Yang. They continue to host a podcast together.

Mr. Yang’s team has said that Mr. Graumann helped the campaign get started but that it wanted to put New York political experts in charge of the team.

At a recent candidates’ forum, Mr. Yang mentioned Ms. Ahuja in response to a question from Maya D. Wiley, another mayoral candidate, about the Business Insider article.

“One of my co-campaign managers is a woman of color, Sasha Ahuja,” he said. “I could not agree more with the fact that you need, you need to have women in positions of leadership in order to actually operate at the highest levels.”