You asked for advice. Mine wasn't what you wanted to hear and you ran away. I will respond because 1. I'm not your daughter and you can't control me and 2. I care about your daughter and am challenging the paradigm that got her feeling depressed and suicidal while you seem to want to think that that very paradigm is all good and she just needs a therapist and a good PIMO friend.
I get why you would be concerned about her going onto sites where she might find things out for herself with her suicidal feelings. She didn't catch those feelings from going online though, she caught them from the life she's already living. Yes, isolation can make one feel suicidal, like living in a cult where you don't fit in and know you don't fit in especially once you start seeing through the bullshit for yourself. Been there, done that, got the t-shirt. That doesn't mean that my situation is defining here either. You asked a question. Don't do that if you only want the answers that you want. You can't control everything.
Regardless, you don't get to control your adult daughter, you coming here asking for ways to help her is kind but also *could* be boundary crossing. Your daughter is an adult and needs to be able to handle herself and stand on her own two feet. She and she alone has to find her way out of this in her own way. It may not be your way, and your way may be unhealthy for her.
I fully admitted that I could be wrong in my assertions and tried to have a dialogue but you're so defensive (probably because something hit home) that you are willing to throw away ideas and discussion because you seem to be struggling to admit that you might just be in the wrong with some way in which you're handling this. So my question to you would be, is there anything maybe you could have done better? Is there anything you could do better now to be there for your daughter without controlling her to encourage her autonomy and growth as an adult human? I know that you read something about suicide on the internet, but might it be that there could be more to the story? Have you discussed with your daughter what her feelings are and how you could support her rather than deciding on your own what she needs and how to help?
What is it about someone questioning the situation that makes you run away? Could you be missing out on some potential benefit through the questions of others, something that could actually help your daughter that you care about? Why do you run from this honest and open questioning?
Do you trust your daughter? Do you feel like you've equipped her to make good decisions on her own? Why do you think that she'll come somewhere like this and be told to rip the bandaid off and be shunned like you said? Do you think that she will simply follow suit because someone on a forum told her to leave? What if disassociating and calling it quits on the JWs was best for her? Could you envision a scenario where that could be the case? How would you feel if she disassociated and was happier being free? Would you be able to be happy for her, or would you feel threatened in some way because she took a step that you haven't taken?
Yes, I am going to question you (and I know sometimes the questions are hard) and the situation. I do it to help, especially since you have a daughter feeling desperate enough to contemplate suicide. Doing the same thing over and over and expecting different results is insanity. Something clearly needs to change. You are her father. In this time she needs you, if you are truly healthy for her, which sadly often parents aren't. With or without you she'll find her own path if she doesn't feel so much shame from violating her promise that you pushed her to make to you regarding finding her own path by researching online. You don't get to be the only source of information for her, procuring and deciding what she can look at and what she can't, or even what she can or cannot handle. In fact, behavior, information, thought and emotional control are the BITE model exerted by cults on people that they want to control. We're all guilty of thinking that we know what's best for someone and trying to control things that aren't ours to control.
You want to help your daughter and that's a beautiful quality. You wanting to control her, even if you believe it's for her own good, isn't necessarily healthy even with good motives. She has to find her own way ultimately.