Prosecutors have accused a 22-year-old woman and a 15-year-old girl of teaming up to beat, rob and throw bleach in the face of a T bus passenger — and cops say the teen’s own alarmed father turned in his daughter after he recognized her in surveillance images.

Lai-Lawnnie Douglas, 22, pleaded not guilty yesterday in Roxbury District Court to charges of unarmed robbery, mayhem, destruction of property and indecent assault and battery. After the judge set her bail at $20,000, Douglas could be heard wailing from behind the defendant’s door where she hid during the arraignment.

The teen suspect, who authorities say actually splashed the bleach, faces unarmed robbery, mayhem and destruction of property in juvenile court. She was held on $100,000 bail. T police said the girl’s father identified her as a suspect.

According to an affidavit from MBTA police, the victim was blinded in his right eye during the attack.

The police report said Douglas and the teen boarded the bus at Dudley Station shortly before 2 a.m. on June 9.

Douglas first pushed and slapped the victim and then reached into his pockets and stole money and a credit card, police said. At one point, it appeared Douglas “deliberately” pressed her breasts in the victim’s face and then rubbed his inner thighs, the report said. Before the pair got off the bus, police said, the teen threw bleach in the man’s face.

After the arraignment, Douglas’ lawyer, Richard Doyle, said the onus was on the “principle aggressor,” the teen suspect. He also questioned the quality of the surveillance video, which he said he hasn’t seen.