NJ Need to sell my daughter's car - I am beneficiary

You might call your local motor vehicle office for your States procedure in this case.
Usually a registration and the title is needed and the bill of sale is usually generated by the seller.
For example: I (your name) sell one (car year make and model-serial number) to (whom ever) for (X amount of dollars on this date) There is a place usually on the registration to sign the car over to the new purchaser.

If you have been appointed administrator over her estate by the county probate court you have the power to sign a bill of sale for you daughter car and handle her legal matters , if not you need to go see the probate judge and he / she will tell you everything you need to do, forms / paper work you have to fill out , you have to be bonded for the amount of her estate, provide the court with a list of everything she ownes, money in back , yeah all that and more .
i had to go through all this when my son died.