Is the prayer of the wronged answered even if their wronging went too far?

Scholars have differed regarding the permissibility of supplicating against an oppressor with more than the extent of their injustice. The preponderant opinion is that it is not permissible because it is a retaliation in which excess is not allowed. Consequently, a supplication that exceeds the wrong done will not be answered, as it constitutes aggression in supplication. What is incumbent upon you is to repent to Allah for what you have done and to seek absolution from your sister. If your repentance is sincere, it is hoped that the evil your sister supplicated will not befall you.