It seems like she's doing this for attention and/or to use as a tool to get what she wants, so... I guess don't encourage her. Expect what you accept, to quote a person I don't remember the name of (who was, in turn, quoting her grandmother). If it ever gets to be too big of a problem, you can talk about it to someone involved or stop interacting with her--I don't know if the site you're using allows you to block users, but if it does, that's an option. Treat her how you would want to be treated (not meaning roll over; rather, do what you would be glad for if you were looking back on that situation). You're an incredibly smart and awesome person, so I think whatever you end up doing will work out. 

Best wishes! 

A friendly reminder from someone who has suffered because of this- mental illness is a hard thing to cope with. To live with, every day, with no escape and often times little vents. It’s best to try and treat every case of ‘mental illness’ as if they’re serious, because even if they are pretending something must be wrong- who would willingly flaunt something so shunned and so taboo in this society? Who knows, maybe something is seriously wrong. I’m not saying ignore it, it clearly makes you feel uncomfortable, but this is something she must work through, and support is more helpful then fusteration or hate. I understand this makes you uncomfortable, but why do you think? Is it because mental illness is so taboo and so hated on or that you yourself have been diagnosed with a similar disorder and don’t understand how someone could just pretend to have this horrible debilitating thing? People have different coping methods. I myself started out yelling my disorders to the stars, hoping hoping it would go away or somehow people would understand and help or just stop judging me on things I can’t control. Now I try and spread as much awareness as I can, so others like me don’t feel how lost and confused I felt. Don’t judge how people deal with issues so shunned in this society, because often times they don’t know what to do. Because people don’t talk about it. And if they do, it’s something like ‘smile more’ ‘your not trying hard enough’ ‘try to lighten up your making us uncomfortable’ ‘you’re just faking it’. Do you know how hard it is to hear these things? Especially with everything else going on? Would you say the same thing about someone with cancer, or a broken bone, or a dibilitating physical disorder who’s only way to vent is by online means because their family thinks God has cursed them and none can save them? I understand certain things are hard to hear. There is such thing as second-degree trauma, where something someone went through has an emotional effect on you as well. But this can help you help them by understanding them better and trying to get them to go to therapy so they can leave their bad past behind, and understanding them will ease away your discomfort. So what I’m trying to say, by understanding and treating their coping methods with support instead of with mistrust and frustration, you can help them ease down on the amount of things they talk about and the amount of confusion they sputter out and the discomfort you get. By understanding them your discomfort will go away. And you might even make a new friend!