Our Freya is very healthy and active and eats like a pony but at 30" weighs in around about 32Kgs. She tends to the lighter build which we like, although admittedly she is a bit light on bone structure. She runs like the wind and is a very contented lass so long as she can get a daily run. We walk for 1 and a 1/2 hours daily and has a big garden which she largely ignores other than mooching about, but she would rather do her mad race round the field for 10 mins.
I wouldn't worry about the scales so long as she is eating and exercising well.
Harriet sound just lovely.