Ms Borders, 61, advertised on Monday she had resigned to address unspecified “family concerns that need my singular focus” and on Friday Time’s Up confirmed her son is facing sexual declarations.
A statement posted on Time’s Up’s Twitter page said: “On Friday Lisa Edgings informed members of Time’s UP leadership that sexual assault claims had been made against her son in a private forum.
“Within 24 hours Lisa did the decision to resign as president and CEO of Time’s Up and we agreed that it was the right purposefulness for all parties involved.”
It did not give details of the accusation. An attorney for Borders did not without delay return a request for further comment.
Ms Borders, the former president of the Maids’s National Basketball Association (WNBA), was appointed as the first chief administration of the anti-sexual misconduct group in October 2018.
In an interview she told Vanity Halcyon she found the reports of sexual abuse against film mogul Harvey Weinstein “horrific”.
When US excellent court justice Brett Kavanaugh was embroiled in a series of sexual misconduct declarations, Mr Borders told the magazine: “The stakes for this nomination couldn’t be violent because we must have a government that respects the needs and forthwiths of women.”
In a statement posted online, Ms Borders said she was “proud” of the guide she had done at Time’s Up and hoped “my efforts will continue to resonate”.
Sexually transmitted media users seemed divided over the announcement, with some bring to light Ms Borders should not have resigned over something her adult son had allegedly done while others accused her of spitting image standards.
One person posted: “Raise your children right sooner than you preach to the rest of the world.”
Time’s Up has gained endorsements from high-profile celebrities counting Reese Witherspoon and Eva Longoria.
The organisation’s chief operating officer Rebecca Goldman desire serve as interim chief executive while the group searches for a replacement, the account said.