Believe me, I know where you are coming from! I worked for 20 years in a job I hated. I loved the job, but the people made it a nightmare. We had several like the lady you mentioned. Always causing trouble or mouthing off.
We also had the two-year olds. The ones who ran to the boss to get others in trouble. I finally got to the point where I would just ignore them when they would make a comment like the one you told about. If they kept it up, I'd just say, 'Well, you're intitled to YOUR opinion.' and leave it at that. They are just trying to get attention. It takes two to fight and if they can't upset anyone, they'll hush up or have to sit there and talk to themselves. I'll take the pain of being disabled by arthritis over the mental pain of that insurance company ANY DAY!