Six years ago I was in your daughter’s exact same position. It’s a long story, of course, since I spent about a year with the ICOC before going to the Catholic Church. My short advice would be you to offer her a book to read called “Catholicism and Fundamentalism” by Karl Keating, especially the second half of the book (the first half is a historical study of an anti-Catholic book). It’s what gave me the reasons I needed to separate from the ICOC (and protestantism in general) and come back to the Catholic Church.
I am a bit worried that your daughter is saying that you are trying to “persecute” her. I mean you are her father. Try to reassure her that you love her and just want what’s best for her, and that these people which she has just met might not. Try to encourage her to think for herself and to love the truth and not be afraid of it.
Some people say that the ICOC has reformed, and it has to a large extent since Kip McKean was forced out in the early 2000s. But in my opinion, the group (not necessarily the members, but the institution) is still fundamentally a cult, because they’re still following the same schema made-up by Kip McKean in the 1970s, right down to the “Bible Studies” your daughter went through. I went through them too. (They are basically the only “Catechism” they have AFAIK) There is a critique of them here that I think is still valid because I went through these same studies. They didn’t get rid of them. Try to get her to read them and consider them.
reveal.org/library/theology/dandersn2.html
The people I met were well-meaning people. They do a lot of good things for people, showing them God’s love in what little way they can. But they are also following a shoddy plan that was put in place by this McKean fellow that doesn’t have the wisdom of 2,000 years of Catholic Tradition behind it, and it has lead and will continue to produce problems.
I would tell you one more thing though:
The thing your daughter has to be prepared for is that since she has already been “baptized”, if she leaves, all the “friends” she thinks she has made will probably not speak to her again. I remember I went off to a university a bit of a distance from where I went to High School. I had to try and make new friends again. So when I found some in the ICOC, I thought great! But then they stopped talking to me. I would run into them when I was at university, and the people that I had had meals with and socialized with WOULD NOT ACKNOWLEDGE ME AT ALL. It was weird on a personal level, but I believe that they would try and justify this by citing Titus 3:10. But you can see how ripping scripture out of context and tradition creates problems.
Oh, and try and get your daughter to seek out the Catholic clubs on campus, like a Newman Club. She’ll meet friends there and they won’t try and isolate her from you!
So if you can, get her to read the book “Catholicism and Fundamentalism” by Karl Keating, especially the second half of the book. It’s what made me decide to leave that Church and become a Catholic. And pray for her. Pray for the Holy Spirit to guide your daughter to the Catholic Church and away from Kip McKean’s creation. Feel free to PM me here if you have anything else you’d like me to say about my experiences with the ICOC or reply ITT.