Mercedes Bristol spent a recent Friday morning in her suburban San Antonio home sending emails, combing hair, answering calls and doing laundry for her grandson. She was tending both to her work as head of the nonprofit Texas Grandparents Raising Grandchildren and getting her youngest grandson Paul Chavez ready for a mariachi concert in the afternoon. Bristol also had reason to celebrate the end of the work week: Days earlier, Gov. Greg Abbott signed into law a bill that will enable thousands more Texans to qualify for the federal Supplemental Nutrition Assistance Program that provides financial assistance, commonly referred to as food stamps.