Best outcome seems to be

a transfer to a different department, given her track record. Second best is a settlement with the company through discrimination and then get a new job. Talk to the big boss first using evidence she has (not the recording yet, it is a grey area), emails or just a recount of what happened. If he helps, wonderful. Very likely not. Then go to next level up. If she is lucky, she will get some help. Problem solved. If not, go to HR and legal and tell them that she is ready to sue if justice does not come. At that point, she will need to be ready to leave. The only thing on the table would be what compensations she would want to take to keep peace with them. I wish I had better ideas than this, but from many cases I knew of, unless she is really lucky that her boss somehow leaves before she does, she should not expect to survive this for much longer. The process will be stressful, but once she decides to fight instead of trying to cope with her boss, it may actually get better since she will be in control instead of her boss. Keep an easy mind, don't stress out. Life still goes on out of work and there are many companies she can work for.