Many estrangements are because the adult child blames the parents for poor parenting in some way, when it really was the choices that she/he made as a teen
My sister was one of those, there was no problem at home, we went to school together until I was 16, nothing untoward, but, she always hung around with the “bad boys” seeing the problems, parents did what they could to discourage her. Despite that eventually she married one, that lasted 2 yrs no kids so no real damage, then she married a really bad boy, 2 children, that was a disaster, husband was jailed, both daughters walked out a 16, one doesn’t speak to her now after 20 yrs
She’s OK now with her 3rd husband, a miserable life all because she got involved with the wrong crowd as a teen