I have no idea what she's actually like, I'm only "damning" one persons account of another person's behavior. The last thing you should do at a new job is immediately set up all the conditions for not only taking yourself down but someone else as well. Not to mention the whole continuously flirting with a married man while being married yourself (again.. at work). I got enough experience to know that type of person, male or female, is not worth pursuing unless you want to deal with big dramatic problems down the road. I'm not saying all people who behave this way are shitty at relationships, just all the one I've been exposed to in one way or another.
Being successful and happy in relationships, even ones that ultimately fail, has a lot to do with avoiding blaring red flags, and in turn avoiding toxic people, regardless of how nice they are, or how easily they laugh at your jokes, or how attractive they are, or how good they make you feel under certain very unhealthy conditions.
I avoided these types of women even when I was single, I can't even imagine giving into this shit with a kid on the line. And, assuming she knows about Slu's kid, she should back off on her own and realize the two of them might be on the road to breaking up a family. Even if someone's marriage is completely failing, let it fail on its own without inserting yourself as a reason for it, again, especially with a child's future on the line.