According to her version of the events, she didn't do anything close to that for 11 years. By her own account, she ghosted, blocked and ignored in the hopes that he would "take the hint" except for when she was bored or lonely. Don't hint. Don't play games. Tell him directly that you're not interested.
You don't know what I have dealt with in my life.
Don't be melodramatic, he didn't ruin her life. He has harassed and stalked her, both of which are completely inexcusable but it's not like he's killing her pets, threatening her physical safety or sending boxes of excrement to her workplace.
Again, by her own account he didn't escalate to harassment or stalking until 11 years after they met. Perhaps she shouldn't have had to but she could have ended this before it began with a firm but polite "No thank you".
Seriously, you have never dealt with this before. Do not pretend that you know what to do.
And quite frankly, even if she didn't, that does NOT excuse this asshole for ruining her life.