Salaam - struggling to help my sister with mental health and rushed marriages

Assalamu alaikum, First, sorry if I use any wrong terms - I don’t mean disrespect. I’m asking because my sister reverted a few years ago and I’m trying to balance supporting her mental health and respecting her faith. Although she hasn’t been formally diagnosed, I’m almost certain she has BPD and that causes very impulsive decisions. A few years ago she met a man through an app and insisted on getting married (islamically) within a week. They had a nikah, had a child, and later separated because he treated her very badly. We were worried at the time - she hadn’t even met him before the nikah. She insisted he was her soulmate, that Allah put him in her life, she prayed for it, and nothing would convince her otherwise. Now we’re in a similar situation. She and her ex have a turbulent co-parenting relationship. I think she’s in a manic episode again. She’s met another man and within two days is saying he’s her soulmate, Allah put him in her life, she prayed for this. She began saying that even before really speaking to him. When I try to be realistic and tell her she doesn’t know this man and might be repeating a harmful pattern, she says things like “you don’t know my iman,” “this is how Allah intended it,” or “we don’t date like you do.” I know Islam has proper ways to get to know someone, and that picking a random man and declaring him your soulmate isn’t the right approach. But I don’t have good responses that she’ll accept. Apparently she’s now speaking to this man and he’s planning their nikah - all within three days - and he hasn’t even spoken to our dad. I want to support her without getting shut down by “you don’t know my faith,” and without undermining her religiosity. How can I gently and effectively help her see the risks and encourage safer, Islamically appropriate steps (family involvement, taking time, seeking medical help) without making her feel judged? Any practical advice, what to say or do, or dua’s I can make for her would be really appreciated. JazakAllah khair.