An NYPD sergeant will lose 20 vacation days for her role in the deadly arrest of Eric Garner, sources familiar with the matter told The Post on Wednesday.

Sgt. Kizzy Adonis agreed to the punishment in a deal to plead guilty to a departmental charge of failure to supervise then-cop Daniel Pantaleo, the sources said.

Adonis had been scheduled for an administrative trial before the end of the year.

Pantaleo was fired on Monday by Police Commissioner James O’Neill following a trial at which he was found guilty of official misconduct for placing Garner in a prohibited chokehold while arresting him on suspicion of illegally selling loose cigarettes on July 17, 2014.

O’Neill signed off on Adonis’ plea deal, sources said.

Adonis was one of two police supervisors who responded to the scene of Garner’s arrest in Staten Island, and cellphone video shows her standing nearby as Pantaleo and other cops struggle on the sidewalk with Garner, who repeatedly gasps “I can’t breathe!”

Adonis, who had been promoted to sergeant less than a month earlier, was charged with failure to supervise in January 2016 and stripped of her badge and gun.

She was restored to active duty last year.

In his review of the case, O’Neill found that while Adonis’ supervision at the scene of Garner’s arrest was “lacking in certain areas,” nothing she did led Pantaleo to apply the chokehold or delayed medical treatment for Garner, the NYPD said.

The Sergeants Benevolent Association declined to comment ahead of a planned Thursday morning news conference.

SBA President Ed Mullins previously called the disciplinary charge against Adonis “bulls–t” and “political pandering to the anti-police rhetoric that’s out there.”

Garner’s mother, Gwen Carr, said she was “outraged and disgusted,” and blasted Mayor Bill de Blasio and the NYPD.

“It’s disgraceful that they waited more than five years, until after Pantaleo was fired, to cut her a deal so that all she’s facing is losing some vacation days and they want us to accept these crumbs as if there is some justice,” Carr said in a statement released by the Communities United for Police Reform activist group.

“By refusing to schedule a disciplinary trial for Adonis, de Blasio and the NYPD are actively participating in an ongoing cover-up because they don’t want the public to know how deep, how wide and how high the wrongdoing in this case went.”

A spokeswoman for Mayor de Blasio said: “The loss of Eric Garner was a tragedy our entire city mourns. For the first time in five years, people are being held accountable and there is finally some measure of justice. We hope that this brings the Garner family some small measure of peace.”