I am guessing it is her own sin that laid the guilt on her. The CC has taught the same thing for 2000 years. The teaching is sometimes hard. That is why many Catholics leave. Just like those in John 6. But forgiveness is always there."Nobody creates mental health issues for somebody else, even you and her other boyfriends and husbands could not have. If she had those no wonder she has been divorced twice."
The guilt that they've laid on her is overwhelming. And guilt is a strong motivator.
Divorce and remarry is a grave sin in the Bible so therefore the Church. She can get forgiveness but she probably wants more than that.
Satan is always at work on us.