I really like Sandie. She's very proportionate. Depends though on what type of show you are at & the judge you draw. Sad to say but a lot of the QH/Stock judges look for the big boys, tall & built like a body builder. I don't bother to show mine in halter in AQHA anymore for that reason.
If you go western, really fit her halter snug. She has a darling head & a good fitting halter will show it off. If you go English show in your bridle.
Pony halter may also be an option if it's a 58" & under category instead of 56". She'd be tough, tough, tough as a pony!
Life is like a camera. Focus on what's important, Capture the good times, Develop from the negatives and if things don't work out, Take another shot.