The first thing i thought when I heard my ex had married someone he'd met online 3 months earlier was dear god I hope he's nicer to her than he was to me.
But I also know what he's told her about me via people still in touch with him. Despite mutual friends I've never met her as apparently she's so hurt for him at how I treated and then abandoned him.
He also presumably can't risk her finding out the truth and realising what a pile of shite she's been told.
They're married and she needed a visa so even if I had wanted to warn her it wouldn't have made a difference.
But I hope, genuinely, that he's not gas lighting and abusing her. And I know, though don't really remember, that people tried to warn me and I refused to listen. He's been through so much, I was the only one who could help him, etc etc etc... I'm grateful I saw the light but it took a while!
So I don't know OP. But as someone's said, if you and his previous ex both give it a go and have no agenda, you might stand a chance at stopping another woman staying in a shit situation.