By gosh, I think you have a LOT of potential for as little experience as you've said you have (I saw your first-time thread a couple days ago). The first photo looks a bit washed out and flat; it needs better, more-contrasty post processing,and her line of gaze leads th eeye right out of the frame. The lovely Queen Anne's Lace flowers are always a nice, evocative motif for portaits of young women outdoors (sometimes called Wild Carrot, due to the smell when the plant is cut). Due to a number of factors, this shot doesn't quite make the grade for me.
The second shot is pretty "active" with her leg placement on a strong diagonal, and her arms placed pretty well, and the strong diagonal line of her eyes creating a lot of visual "tension" between her and the viewer. You have used the entire frame in the "as in a painting" style of composition, which is an OLD STYLE OF COMPOSING, in which the subject touches,or almost touches three or four sides of the canvas...errr...I mean the subject touches or almost touches three or four edges of the camera's imaging capture area. THis is a pretty good picture, especially for a beginner!
Your third shot shows how to PROPERLY FRAME A HORIZONTAL environmental portrait; the subject is w_i_d_e_r than she is tall in that seated pose, and so the camera is oriented so that the subject occupies the majority of the frame, while also showing some of the environment/setting. Again, pretty impressive for a new shooter!