What is incumbent upon one who broke their fast on days in past Ramadans, despite their intention to fast, and has since repented, prayed, and sought forgiveness?

The questioner must repent to Allah Almighty for her negligence in fasting Ramadan, because breaking the fast therein without a valid excuse is a major sin. She must hasten to make up all the days she missed from previous Ramadans since reaching the age of accountability. If she does not know their exact number, she should estimate them and make up what she believes will absolve her. She must also make up the prayers she missed without a valid excuse.