Ok first video: Coming into the fence when you are trotting, you are posting with your hands. Meaning as you post your hands are coming up and down with your body. Loosen up yours arms, so that your hands stay more steady. At the first fence you get a little ahead of your horse. When you are riding a green horse especially you need to wait for the horse to jump. At the second fence you need to stay off the horses back longer. You sit before the horse touches the ground, and you need to stay off it's back until it lands.
Second video: You are getting a little ahead with your upper body here as well, and you are sitting back too early. Really try to focus on waiting for the horse to jump, and staying off it's back until after it lands. When you really start to change this, it's going to feel like forever until you land, and like you are doing things all wrong. I know because I had this exact same problem. Lol. Don't worry though, it will start to feel normal after a while.
Overall you ride very well, and the horse is a cute little jumper. Did you end up selling her?