Few things I see. I know the jumps are small and therefore you don't need to "fold" as much over top of the horse; however, you do need to getting your butt out of the saddle a little higher and longer. You have a tendency to sit back too early which will lead to a lot of problems, one being dropped rails. You also need to work on not letting your leg off the horse over rails/jumps as long as you are. The horse's energy level drops and leads to laziness and tripping. Plus I'm sure your instructor would prefer not to chase you with a whip
You also need to work on sighting distances to jumps. You have a great start and over time that is something to work on. There is a delicate balance of saying whoa and go at the same time to get the right "take off" spot. It is more of a problem when there is a single jump on its own. When you have more then one jump or ground rails before, you seem to do well. Try not to rush the take off when going to a single jump. Think, wait, wait, wait, GO! Doing more ground rail work will build this up. Try counting down, out loud to jumps to your take off spot. Whether they end up being a big spot, or a short, chippy spot, it will get you thinking about judging distances.
You have a great start; with time and practice, you'll be just fine.