I've had to deal with something similar. Anecdote first, if you like? I dated a crazy woman for a few months, who would not leave me alone for about a year. And she genuinely was crazy, as I later discovered. She eventually found my FetLife page and posted a nice big link to it on her blog, for all the world of fellow crazies to see. She had talked about me on her blog over the previous year - she had a little rally of followers. It certainly freaked me out, because through FetLife, people can relatively easily find out what events you will be attending, what you look like if your picture is up and so forth.
Now.... in terms of your ex.
You say you don't fear for your life - so it's just a privacy issue?
You have a couple of options. Either simply ignore her and leave her to it. Or, call her out on her behaviour and try to embarrass her into stopping. Most likely, she came across your OKC profile by accident, or ran a search for your description hoping to find you. Either way, it doesn't say much about her besides what you already know
With my stalker ex? I sent her an email, telling her in no uncertain terms that she had better be removing the link to my FL from her profile. I reported her to FL... but... unfortunately discovered that really, anything we put online is our choice. It's a public forum and by involving ourselves in it, we relinquish our right to privacy.
You know her best, so I say choose the option that makes the most sense for you. Want to avoid drama? Probably best to let her get on with it - she'll get bored if she doesn't have your attention. Don't mind drama but want to give her a piece of your mind? Then tell her politely and firmly. Even sarcastically... "Can I help you with an unresolved issue, because it has been brought to my attention that you have been asking friends about me lately and reading my OKC profile?"