Saddle Drama- Need Help

Any tips on how to get this girl to wear her saddle? She is a total drama queen as soon as I put it on her. She flops over and acts like she can’t walk. I’ve tried it multiple times and she somehow slips out of it within hours. I bought The Chicken Chick’s standard size saddle which works perfectly well for my other lady. Are there other style saddles that may work better for her? Or do I just let her suffer with a bare back?