You can't appeal a guilty plea. So, they are agreeing to the punishment they court dishes out to them. In Sidney's case it really is no big deal. Probation and a $6,000 fine. She could spend them much on lawyers in a single day, easily. All misdemeanors.
For Chesebro though, there is a Felony conviction. That has some serious repercussions, including probably loss of his bar accreditation and ability to practice law, forfeiting his right to own guns, right to vote and various other ways that convicted felons are encumbered. It's not a small thing.
I believe a coercion claim mitigates a plea?