Try living with that. Its not a good thing. Look in particular at 'choices'. In nature there is neither good nor bad, merely consequence. That will slack off in time if she can hang in there.
Abortion is like murder but it happened and that's reality.
She made her decision and no one has a right to make her feel guilty, Christian or Non-Christian. She will feel guilty more than anyone who condemns her of her act by herself. Herself will realize the actions she took and as friends of those who made that decision, we still should comfort those in sin. Who can cast stones at anyone that is human. We all have sinned.