Re: communicating with your boss through facebook
Personally, if she felt comfortable enough to add you on facebook knowing that you would be aware of her status updates, then i think it is not only right but also somewhat complimentary for you to comfort her or inquire if everything’s alright.
A small gesture, but who knows how far it’ll go into making her feel better.
Besides how do you know she’s not observing you by doing this. Every employer measures your attentiveness differently, if your probation period is about to be up, this may be your last test to see if you observe well and act accordingly. 
Okay, that’s just my wild imagination. But what i said first still counts. 