[@Silver Fox]???? of course she doesn't know alex well. I mean, they just met. She's going off of everything she's seen and heard from her since they met. Saina is more logical than emotional, she draws conclusions based on what she knows. But then, so would everyone. Thus far, all Saina has seen from her is, well, what shes pretty much already said. 
And thus far, that's all shes seen. She wouldn't know if Alex is self conscious or depressed, etc etc and for good reason.