I think overall this these are a nice set for a first attempt; a few thoughts: The main issue IMO is your choice of location. It really doesn't seem to suit the occasion. In #1 I see a couple of things; one is the shadow which appears to "grow" out of her head across the water and the other is your angle. Generally for materinity work we want to shoot lower in order to accentuate the pregnancy. The higher angle is one often used to minimize the size of larger clients and IMO, is counter-productive.
#2 has beautiful light (and I'm not a huge fan of flare); I would crop a bit of the top, just to get rid of that bright, white sky. Again, I think you could have been a little lower, but the angle isn't bad. The ground water however is returning bright/blown highlights and pulling the eye away from the subject. I would be tempted to burn a lot of this in/clone it out to reduce the highlights around her. The last one has nice light and a great expression. You've got a lovely rimlight on her hair, but again, the highlights from the water are hurting the image.