#1 is the best. Sharp, good use of enivronment, good posing.
#2 light is too harsh, not a flattering pose.
#3 seems soft
#4 kind of a weird pose; since we can't see face or profile, hard to extract anything from it.
#1 is technically pretty ok, light's a little flat. Looks like a Senior Portrait, for whatever good or bad that is worth.
#3 is interesting, but I don't get it. It's soft, it's pretty green, it feels like it's going for something but I don't know what. Maybe it's just botched, maybe it's an idea that isn't coming together for me?
I like #2 far and away the best. I like b&w, I like a lot of b in my b&w, so I am prejudiced. I feel like it projects the heat of the day and an erotic heat all tangled together. It's very Liz Taylor, very Marilyn Monroe, on their best days. It's nothing like a senior portrait, it's nothing like a portrait at all. It's not a picture of Beth at all, arguably. It's pretty decent at being whatever it is, though.
#4 is similar, but the color and less dramatic handling of tones takes away from it, it's trying to be a more ordinary thing and failing at that, and also failing at being #2.
She is beautiful and these are nice but, imo, each of these has significant flaws.
1) background is way too bright and intrusive, the light on her is rather flat and non-luminous (and gaping space above)
2) & 4) awkward poses, framed oddly (imo) with brightish areas that are unimportant.
3) I can accept the greenish tinge and the soft focus but the tilted edge and her placement so far too the left are disconcerting.