Well, I can only speak from experience so I'll just say dating a girl with a kid is a bad idea, especially an infant. Whether you like it or not, you're going to have to see this dude(her ex) and hear about him way more than you care to.
I'd say hit it, hang out casually and whatever else you would normally do with any other friend, but leave it at that. It sounds really misogynistic but she has two guys gunning for her and she's like a kid in a candy store at this point, eating that shit up, trust me on that.
