I've actually ordered a whole set for her but I don't want to feel like I'm taking over her either as that's her only horse. I did send her a text saying I am incredibly grateful but the way she's texting makes me feel like she thinks she's asking too much.
^ that can work, or just tell the owner how happy you are with the horse, u love it and say that she isn't asking too much etc x
Buy something for the horse? A new saddle blanket maybe?