This poor girl seems mentally ill. I don’t understand why people couldn’t just reject the rigidity of Satmar and the like and just become frum Jews.
She was seemingly always “off the derech” as she did not have or retain a love for Hashem and His Mitzvos. It’s a prime example of culture clash and has little to do with religion.
As for those who are blaming her, why? Do we want this type of person within frumkeit? She is rebellious against G-d and His Torah, not just Chassidus. if she was, she would just become a regular religious Jew.
I too was rebellious. I gave up eating trief, dressing immodestly and dating gentiles (all accepted and expected in my family). Maybe I should write a book!
The frum world, from MO to Yeshivish should be open and accepting of those off the derech and be available to them to find the proper road back. I would gladly have her, her son and her non-Jewish boyfriend over for Shabbos.