This is what I was thinking, too. Unfortunately, once the time is past, it’s very hard for anyone outside of the person to get working on the faith formation, self-discipline, and moral code.
I was thinking of my sister when I initially responded to the OP, who is basically as you describe. We grew up in an intact family, but I wouldn’t describe it as “fully functioning.” Once I got away I was able to see how dysfunctional it was, even though to many people on the outside it looks like we were a wonderful, happy, wholesome family.
I’m at the point where I think my sister has to fail, really fail, to see that she needs to budge to do anything. I’ve tried advice, I’ve tried offering assistance (which has never even been received with a “thank you”) and…nada. She wants to live on her reddit threads and read/write fanfiction. Which unfortunately it seems like my parents are going to let her do as long as she wants. She doesn’t have fancy hobbies. All she needs is an Internet connection and she can waste her time fabulously.
I pray for her. That’s about all that I’ve gathered I can do that will help at all.