Of the two you posted, I like the second best. Not too sure what people expect here regarding constructive criticism, but I for one really value it, as that's how I have learned. So even though I haven't seen much here, I'll take a chance and say that I like the expression in the first but am a little bothered by the position and brightness of her right arm. I find that it distracts from the face, which is what portraits are all about. The lighting in the second one appeals to me more for its drama. Just my € .02.