Welsh ponies!! What more needs saying! So intelligent, so feisty, such little demons! Ive had a few, the last being a Section C mare that my little girl learned to ride on. When I say "learned to ride on" I mean the HARD WAY!! At home she would drop her shoulder and tip my daughter off 3/4 times a ride. At shows she strutted her stuff every time and won everything!
One day she threw my daughter so many times that she was badly winded. I saw red Im afraid. I said " somebody get my saddle"

I changed saddles on the pony and for the next half hour had the ride of my life! She was doing 2-time changes at the end ( in fairness she had been taught these years before!).
That pony was a witch but I adored her. Sadly she was only 13hh: if she'd been 15hh I wold still have her.
Keep going with your little welsh girl: it will pay off in the end in spadefuls. Have fun!