Not quite sure what you mean by only focusing in the left upper corner, to me it sounds like your AF system is broken and it needs to be fixed, but I assume you would have said that and not looking for a solution.
One issue with the rebel is you cannot manually adjust the autofocus so if you lens is off, which happens more than you would like to think, it will never correct itself when using the viewfinder. Solutions for you, use live view and focus that way, it uses a different technique and would be more accurate or use magic lantern with focus peaking. You could send in your camera and lens and have them calibrated with each other, epsecially if under warrranty. Replace your focusing screen for one that will better show the DOF when using fast lenses.
Im not a fan of black clothes with black hair (roots), everything just merges into one big black blob.
too much brick in #1 for a portrait and of course the focusing brings my eyes to the wall and less to her.
I like the face and expression in #2. I dont like the color scheme oranges red hair tips, orangish red background and way too busy with all the writing. A little underexposed and I still do not like the big pole splitting her body into two.
maybe have your background further away so you can get better isolation.