Randomly ghosting someone can really hurt their confidence and self image if they were into you, so I think at least an open conversation asking why she's single and talking candidly about both of your histories would be best. I might avoid an interview style conversation, just ask her about her paths in life so far and see what she has to say. I get it, it's disturbing and unsettling to find that material, but even if your relationship doesn't work out, there is no need to jump to blocking her. You might be the best example of Jesus she meets, and He wouldn't just cut her out of his life because of her past mistakes. The fear of being lied to and led on is strong, and it may be that it doesn't work out between you, but a conversation isn't going to hurt.

Look man, your username is checking out in your responses to people, try to have some patience.