[LeoRose]

It's always best to rule out a physical reason when a dog starts refusing to do a behavior that they are fluent at. A full physical exam, and possible blood work and x-rays, depending on what the vet thinks, are in order.

 

[LeoRose]

Sigh... I hear you on vet bills you can't afford. I was flat broke when I had a male cat with a urinary blockage, which is a true emergency, where the chances of him dying without medical intervention were high. Care Credit saved the day, and Bigfoot.

I'd quit asking her to try rolling over in the meanwhile. No point in asking her to do something that she can't do, and frustrating both of you.

 

[LeoRose]

I would just stop asking her completely. Give her a break for several weeks, and if you do try it, keep it really low key, and don't keep insisting if she doesn't do it.