First of all cute pony! She looks like a sweetheart and is very pretty =]!
I'm not sure what stepping is so I will just critique your position. Overall you look great, just a few little things to remember. Heels down and keep your leg underneath you (I think you may benifit from shortening your stirrups a hole or 2). Keep your shoulders back and head up. Your hands are a bit hard to see but in a couple pics it looks like you have piano hands so just remember to keep your thumbs on top. I hope I helped some !
And gallop is what we would call a canter. I have a German friend and they use that for canter and gallop :)
Considering it looks like she's in a dressage saddle long stirrup length is acceptable, although I think your really not supposed to have to reach your foot down to be touching the stirrup, I would move it up a hole or possibly two. Your feet are too far in the stirrups, but thats probably from reaching for the stirrup. Very cute pony :)