Melissa - howdy - welcome to the fold! I am glad to see even someone new sticking their neck out for a little critique.
Ok you already know about trees coming out of her head.....but what you also forgot about it the rest of the background. Let's imagine the trees in the head thing are not there -- the background is sparse grass/gravel/dirt that does not complement the beautiful girl. I shoot a lot of weddings and I am always moving people around to find a background that is suitable for the subject --- sometimes moving even a few feet or shooting from a slightly different angle can make a HUGE difference.
Also - I think you need to study poses - get fashion magazines - I am not exactly a girly looking guy but I am always picking up fashion magazines - so I can take in trends in fashion and poses.
In taking your first photo - my initial thought - lets say you just had to have the girl on the pic-nick table -- I would of had her sit in the middle of the table - pull her legs up to her chest - have her arms around her legs - sit forward and ask her for a cute look- take it from a little higher angle looking down a bit - and see how it works with her etc.
The second photo--- well this needs work also -- the location looks fantastic - the angle is good maybe a tad high- I love how you have the sun on her back/side - but you made a crucial mistake - you cut her legs off --- you needed to get in for a tighter crop or back up and get her legs in --- again more refined poses would make this killer. You have the girl/location but made some beginner mistakes.
Thank you for your honesty! There is nowhere to go but up, right 
I actually do have the full body of the second shot - several actually. She just happened to have the prettiest smile in this one. Why does that always happen? Posing is definitely where I need the most work. Until recently, I've only taken photos of my children, so I'm still trying to figure out how to tell people what to do with their bodies. I will definitely get some fashion magazines. That's a great idea. Thanks again!





