Welcome to the forum, and great first post.
It's nice to see fellow artists.
Only minor critiques I'd have to say are that I'm unsure how the muscles are being portrayed around the hips on the left image (it looks like the buns are trying to be emphasized but I don't know if they'd show from a frontal view), and the frame of her face looks slightly jagged in the right image. The ear looks a tad tiny, but that could easily be a style aspect.
Some very good aspects are the intricate details on the tiny wrinkles on the bikini on the left image, the thong is stretched realistically, and the poses are nicely dynamic, not just completely static standing poses.
I just want to try and provide more commentary than "lol nice boobs" or something.