Does anyone know if there are any laws that explain the length of time a person can take off for a death in the family ? - Being within the 3rd degree of relationship ?

There are no laws in any state that give an employee any rights to bereavement leave.

Such leave is solely at the discretion of the company and MAY be written into company policy, such as how many days may be taken and what deceased family members count.

ScottB is correct again.

This is ultimately an issue that will need to be addressed internally. I suggest double checking your employee handbook or discussing the issue with your boss or HR. Either should shed light as to how your company handles similar requests.