James,
Good work mostly. I think we ought to look at photos 1 and 5, the first and last shots, and ask, "Why are you framing these as horizontals??" it makes absolutely no sense whatsoever to frame those shots as horizontal compositions.
Shot number three,however, is a justifiable, good use of a horizontal composition: she is seated on the ground. The background is a lovely park setting. Her body is positioned in a way such that she is wider than she is tall...and the background is actually interesting.
In the first shot, we have a black space on the left hand side of the frame....and the girl has the top of her head clipped off because the camera was horizontal....and basically the entire left hand side is nothing but BLACK background. In the last photo, her head crowds the top of the frame,and 75% of the entire compositional space is devoted to a blackish background.
Contrast those two shots with shots #2 and #4, your two verticals...in those the girl is actually shown. We can see her arms, hands, bust,and torso...we actually SEE the GIRL. In this set, you are showing us 40 percent verticals and 60 percent horizontals, and two of the three horizontal photos are bad decisions, straight up. (I actually know James via PM's spanning months, and I don't want to appear to be harsh on him--I like the kid and think he's progressing very wonderfully and rapidly.) These shots have pretty good lighting and processing, and in fact,look as good as senior shots I was browsing last night from a studio on Facebook. A studio I should mention that BOUGHT the name of a well-known departed local photographer and one of my personal mentors. I looked through their 2009 and 2010 senior galleries, and saw the same type of processing as this,and also noted an over reliance on horizontal framing when verticals would have boosted the shots to another level entirely.
I guess what I want to drive home is--look at shot #3--that is a justified horizontal composition!!! It has a reason for being horizontal! But shots #1 and #5 do not.