Beneficiary of what: a will or an insurance policy?
If she is named beneficiary of an insurance policy, then the money is payable to her and there is no need for probate.
Find out from the employer what the assets are. It may benefit you to be executor if there are assets going into the estate (you would collect a commission), plus the girlfriend has no legal status as an heir if there are other assets going into the estate, and then those assets would need to be probated and distributed to legal heirs: relatives.