Is your 1471 based on having 2 kids in college. If it is and your daughter does not attend, your EFC will be more, reducing your son’s Pell.
If your daughter is working full time living in your home and you are proving more than half of her support she is a number in your household, but not a number in college.
If she is not in college, your EFC will change, which means your son’s Pell will change.