Unfortunately, there is no right to severance, unless you have a written employment contract specifying it; otherwise, without a contract, all severance is voluntary on the part of the employer, so to the employer is free to decide whether to pay it, what conditions to put on paying it, and whether an employee has honored those conditions. So the employer could, in its subjective judgment, decide that your family member has failed to act professionally and decline to pay severance and/or terminate her early. There is no objective standard of what is "professional"--it is entirely up to the employer's judgment.