Lucas Leonard, 19, died in October after he was severely beaten in an hours long "counselling session" reportedly aimed at getting him to confess his sins.
His younger brother, 17-year-old Christopher Leonard, was seriously injured.
On Tuesday, a grand jury recommended a charge of second-degree murder against Tiffanie Irwin, the 29-year-old pastor of the Word of Life Church in Chadwicks, New York.
The brothers' father, Bruce Leonard, 65, is charged with 13 criminal counts including second-degree murder, kidnapping and gang assault.
Leonard and the teens' mother, Deborah Leonard, were among six people arrested in October on preliminary charges of first-degree manslaughter.
Deborah Leonard was not named in the grand jury indictment, but she is scheduled to appear in court on 2 December to face separate charges of first and second-degree assault, her lawyer said.
Also named in the grand jury indictment are: Traci Irwin, David Morey, 26, Linda Morey, 54, and Joseph Irwin, 26, and Sarah Ferguson, 33, the half-sister of Lucas and Christopher.
All five are charged with second-degree murder, kidnapping and gang assault.
An eighth person, church deacon Daniel Irwin, 24, faces charges of second-degree manslaughter, kidnapping and gang assault.
Last month, Christopher Leonard testified at a preliminary hearing that Irwin organised the so-called counselling session.
He said he and his brother were beaten with an electric extension cord fashioned into a whip.
Christopher also said he attempted to resuscitate his brother before the boys were loaded into two separate vans.
Lucas was taken to hospital, where he was pronounced dead.