Jhosephine wrote...
Seeing the "I"m fine, don't worry about me" response from her with Thane constantly made me want to strangle her, how the hell can you be fine all the time? Last I checked you were human, Shepard, not Elcor!
Could just be me though 
They are in a war situation, uncertain about anything, far away from home. The notion that they will probably die lingers on everybodies mind, making the atmosphere unusualy tense.
Fear is like a virus among the crew, it lies dorment with everybody waiting for a trigger. It takes just one person to panic a little and ship-wide morale comes crashing down like a house of cards.
It's Shepards duty to stay strong and safeguard Morale. She, as the unquestioned leader of the mission, serves as an example. Wether the crew realizes that or not.
I think it's hard to live with such tension, such fears, and allowing yourself to dwell too much on your personal feelings. It's even dangerous. I understand her posture, though I agree we're left in the dark a bit, untill she went to look at the picture that is