Definitely A+ grade photos you've taken! Fantastic!
A+ grade coz she is hot? The pic is just so so
Sexy? The bikini is too big for her (very obvious in pic 3) and you should have gotten her to actually try to have an expression on her face. As it is, she either looks stoned or "WTF are you pointing that camera at?"
Of all pics, Pic 3 has the most potential *if* she had adjusted her top properly or gotten a correct-sized bikini.