What is the expiation for, and the sin of, a girl who committed adultery and became pregnant by a married man, then aborted her pregnancy fearing scandal, and what are the consequences for those who helped her with the abortion?

The girl committed an abomination and unlawfully killed a soul. She, and everyone who assisted her, must perform sincere repentance (Tawbah Nasuh). She is also obligated to pay the Ghurrah and the Kaffarah (expiation). The Ghurrah is equivalent to one-tenth of the mother's blood money (Diyyah), and it is distributed among those who participated in the abortion if they directly caused the miscarriage. As for the Kaffarah, it is obligatory upon each one of them individually. If the assistance was merely guidance, then only repentance is obligatory. If a group of people kills one person, then each of them is subject to retribution (Qisas) if the act committed by each of them would have necessitated Qisas had they acted alone.