Age and/or gender discrimination

50 yr old female doing excellent job for over 5 years, promoted, rated highly. New manager takes away all job responsibilities, gives job to a 1 yr employee with no experience or transition of information. Job is crucial, working with government auditors and subject to liability if not done correctly, so definitely isn't a job for an inexperienced employee. Office politics could be a factor or the fact that the no. 1 company goal is to reduce budgets and headcount. New employee now has 2 other people helping to perform my job. I'm given busy work in an area that requires job experience I don't have and can't get - would have to get a new education in a field that I'm not interested in and have no experience with. Other managers said it wasn't fair and that they didn't know why.