1- If it seems that she really did repent, she is genuinely regretful, and she seems to be an amazing person, then remember that Allah is merciful and He forgives. We all make mistakes. What’s important is that we learn from our mistakes and truly repent.
2- Reflect on Sura Furqaan verses 68-70. See how Allah describes their repentance, and how their past bad sins get converted into good deeds.
3- I recommend reading this Du’a daily:
https://www.duas.org/Amn.htm