I'm 5 foot 7 and my 17hh horse was 172 cm at the wither (which is how tall I am), so I'm thinking that horse is likely to be smaller than 17hh. But hey, it probably doesn't matter, I just love details, so forgive me if I appear argumentative!!
I do have a soft spot for Irish Hunters though, and her mare is lovely. At least Alex can actually ride!!!
It still baffles me how Lydia's lower leg can be so far forward when it's not supposed to be! If I was teaching her to ride, I would put her on the lunge for several weeks and make her work without stirrups. She would really hate me then.
(She would develop better balance though! lol...short term pain, long term gain).