Just two things I wanted to bring up.
When you go up and down, your hands should remain steady so, like someone else mentioned, everytime your hands move, they don't pull on the horse's mouth. This is what's causing her to move her head out of that nice flexed position sometimes. Try to relax your shoulders and rise between your arms, keeping your hands as still as possible.
Also, I know you said she's lazy, but I noticed your feet were moving back and forth while you post. Getting your feet to be still is a result of two things: position and strength. Even though you said you want to ride dressage, try standing in a two-point position while you ride for a little bit to get your foot back just a hair more underneath you. This will give you the balance you need to make that posting action less effortful, and also help to get your heels down. It will also help improve your leg strength, as you should not be posting from the stirrup, but from your knee, so when you rise and come down, your inner thigh muscles will be what you are using to do that, and your foot will be still.
You are doing very well for the experience you have, and I personally think that horse is very good for you. Great job!
Last edited by hennisntacanibal; 10-05-2011 at 02:48 PM.