Dear friend,
So long as one is repentant, any sin can be forgiven. Even though having an abortion means automatic excommunication for the one who has the abortion and the bishop would ordinarily be needed to lift the excommunication, in the United States the bishops have given that ability to all priests who hear Confessions.
So all the person needs to do is go to Confession and she may again receive Holy Communion.
Fr. Vincent Serpa, O.P.