There are a couple of different possibilities here.
If the profit-sharing program is part of a retirement plan (401(k) or similar), then it is controlled by federal ERISA law (Employee Retirement Income Security Act). As such, the plan cannot refuse to pay "vested" benefits to any participant (that is, benefits to which the participant was already entitled to at the date of termination of employment).
If your sister-in-law is not provided with a means to rollover her retirement to a "rollover IRA" plan with an independent institution, then she can file a complaint with the U.S. Department of Labor, Employee Benefits Security Administration, and the EBSA will probably be able to get the money (click here
If the profit-sharing plan is not ERISA qualified, then your sister-in-law would have to sue the former employer for the failure to pay the benefit. For an employment rights attorney referral, see this link
In some cases, the failure to pay benefits due at termination fall within the scope of a wage claim, subject to the authority of the California Divilsion of Labor Standards Enforcement (DLSE). The general rule is that if the profit sharing was earned prior to termination, in whole or in part, then it is a benefit of employment, and DLSE can accept the complaint. So, before she contacts a lawyer, your sister-in-law may want to file a wage claim and see where it goes. See this link.
Please let me know if I can be of further assistance.
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