If you are asking what legal protection she has to walk out or lash back out and still keep her job, the answer is none - not in MA or any other state, either. A hostile work environment means the same thing in MA that it does in the other 49 states - if it is not based in a characteristic protected by law, then it is not an HWE and does not offer any kind of job protection. She is free to complain to HR but if it is not illegal harassment as defined above, then HR is not obligated to take any action. I'm not saying they won't - just because they're not legally obligated to doesn't mean they aren't going to do anything at all. But neither HR nor upper management has a legal obligation to make her treat everyone nicely or to fire her or to transfer your friend or to take any action at all UNLESS it is legitimately an HWE as defined by law. She is free to quit but she may or may not get unemployment and she will not have legal recourse. She is free to look for another job and quit when she finds one.