Is assisting in abortion a sin, what is its expiation, and is it considered killing a soul?

Aborting a fetus is a reprehensible act, and the sin becomes greater after the ensoulment, because it is an unlawful killing of a soul. Your assistance to the girl in aborting is helping her commit sin, and makes you a partner in it, as Allah Almighty says: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." Lenience in interaction between men and women leads to such affliction. It is incumbent upon you to repent sincerely and perform many righteous deeds. If the abortion occurs after the formation of the fetus, blood money (diyah) is due from whoever directly performed the abortion, and some scholars have made both expiation (kaffarah) and diyah obligatory.