A 25-year-old Queensbridge woman last week pleaded guilty to fatally shooting her sister at a party celebrating the victim’s 27th birthday.

Melanie Webb, 25, admitted she also shot her sister’s boyfriend on March 26, in the apartment they all shared.

Tara Webb was struck once in the chest at about 2:30 a.m., and was pronounced dead at the scene. Law enforcement sources said Melanie Webb shot her sister on her bed, then turned the weapon on Terrell Carmichael, shooting him twice in the torso while he was in the shower at the Long Island City apartment.

Carmichael was taken to New York Presbyterian Hospital, Weill Cornell, where he eventually recovered from his injuries.

Police sources said investigators initially suspected Carmichael, an alleged drug dealer, of killing Webb and turning the gun on himself. Police set their sights on the sister as the shooter after they interviewed witnesses and party guests.

The sisters shared the apartment for approximately 10 years, neighbors said. Tara Webb had a four-year-old son, Eric, who also lived in the second-floor apartment.

Neighbors told reporters they do not believe Tara was the intended target of the shooting.

“Melanie wanted Carmichael out of the apartment and he laughed at her when she told him to get out. So, Melanie took care of her business on her own and Tara got caught in the middle.”

Webb pleaded guilty to first-degree manslaughter in exchange for 25 years behind bars and five years parole.

During the sentencing, Webb turned to her sobbing mother and mouthed the words, “I love you.”

Webb’s mother, still sobbing, walked silently from the courtroom as her daughter was led away in handcuffs.