Good afternoon. My name is XXXXX XXXXX I will do everything I can to answer your question. I am very sorry to hear that your friend's hours have been cut.
The general rule in California is that, absent a specific agreement to the contrary, employment is "at will." At will employment can be terminated or the terms changed (such as hours) for any non-discriminatory reason at any time, regardless of whether the basis is fair, reasonable, or even true.
The one very impotant exception to the above principle that is relevant to your concerns and of which you are aware is that an employer cannot terminate an employee because of his or her age. That would be a violation of the Age Discrimination in Employment Act. So, if your friend can prove that her hours are being cut because she is now "too old," that would be illegal.
The problem with alleging age discrimination is that is it very hard to prove. The U.S. Supreme Court recently raised the evidentiary threshold for these claims by ruling that a plaintiff alleging age discrimination must prove that "but for" their age, the same adverse employment action would not have been taken. (See Gross v. FBL Financial here: http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=US&navby=case&vol=000&invol=08-441
Basically, an age discrimination claimant can no longer prove that age was one motivation of several--they must prove that their age was the driving force behind termination above all other things, and they must prove this by a preponderance of the evidence.
What an age discrimination would would want are comments that derogatory about their age, a culture of favortisim toward younger employees, or a layoff or other adverse employment action targeting other older employees, or proof that they were replaced by someone substantially younger and less qualified. This is the sort of evidence--preferably more than one of these things--that juries look for in these cases.
In your friend's circumstance, her responsibilities are being given to an employee with far less experience who is also much younger. Unless there are legitimate business reasons for this decision, it certainly makes age discrimination a plausible explanation.
Your friend would be wise to give some consideration as to whether other evidence is existing (i.e. negative comments about her age, the same thing happening to other older employees, etc.). A case on the limited facts you have described is bordeline, but with additional evidence it could be very strong.
In short, although employment is ordinarily "at will" and thus subject to a change of terms at any time, employers cannot take adverse action on the basis of an employee being more than 40 years of age. Given that your friend is being replaced by someone younger with less experience, that certainly raises a question of age discrimination and potentially forms the basis for a claim. However, additional evidence of discriminatory intent, which can take a variety of different forms, would be what your friend would need to have a truly "strong" case.
If your friend is interested in proceeding forward with a claim, she would be well served to locate and consult with an employment law attorney in her area. Most attorneys handle this sort of work on a pure contingency fee basis. If you don't know, a contingency fee arrangement is one in which the attorney receives a portion of the client's settlement or award as his payment, typically 1/3 of the total amount. If there is no recovery, the attorney does not get paid. The client never pays until the settlement or award is obtained (except perhaps to cover the filing costs for his claim).
To locate an attorney close by, see here: http://www.cela.org/?page=4
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