Your sister is only 30 years old this year. Do you have any kids? Your sister is divorced now, it's just a little pain in front of her. If she wants to live like this all her life, her life will be ruined and your parents will have endless pain.
Although I seem to have suffered a big loss at present, it is too painful to gamble with such people all my life.
If you have a child, you must deal with the child's problems well, or you will go to court if you can't.