Actually, in an "at will" employment relationship, a company can fire a worker for any reason or no reason at all, with or without notice. That is so long as this action does not violate the terms of any applicable union agreement/employment contract. Accordingly, if your brother has no such protection then, yes, he can be terminated. As for your demotion to a less experienced male employee, as a woman you may or may not have a claim for sex discrimination. However, based on the limited facts presented it's hard to say for sure. At this point you can contact your state's department of labor and/or consult directly with a local employment law attorney about your situation.