My parents live in Texas. Does my mother have to file my deceased fathers will with the Superior Court of the county they live in?

Texas does not have superior courts.  The Will is filed with the probate court, county court at law or county court, depending on the county where your father lived and died.  If your mother does not submit the Will for probate, you can hire a probate lawyer who practices in that county to file a motion demanding the Will's production.  Note that if there is no Will, the distribution of your father's possessions will pass to your mother unless he had children who are not hers.