Fellow employee having to file bankruptcy because of medical bills, is her 457 plan actually safe?

My coworker and I have been good friends for years. She and I talk about everything together. She came up to me because I talk about stock market stuff once in awhile about her having to file bankruptcy. She was somewhat frantic because she has massive credit card debt ($55k). She also leases her vehicle ($32k msrp if that matters). She said the biggest reason she must file for bankruptcy is her medical bills ($190k)! Her situation is unique, and I will tell you after speaking to my stepmom who is a top worker at one of the biggest health insurance company in the country, my coworker needs to file bankruptcy because of her situation.

Years ago this same lady and I went to training together and graduated from training in the same class. We both signed up at the same time for Deferred Compensation and both of us maxed out the available contributions to our 457 plan (we are both government full time employees if you are questioning why a 457 instead of a 401k). My friend stated her 457 contributions are safe from bankruptcy. I could not believe it, but after doing a little research it appears she is right. I did ask her how much she has in there, since if she had a big money pot bankruptcy court might find a way to fudge the rules… She said $42k. My coworker is 100% certain her savings/checking/car are unsafe from being taken in bankruptcy, but is 100% certain her 457 is untouchable. I disagree though, because it seems like common sense it is an asset and therefore can be garnished in bankruptcy court. Who is correct here, her or me? Any links to sources greatly appreciated to help her feel at peace.