Hudson will sing the national anthem before Sunday's game between the Arizona Cardinals and Pittsburgh Steelers. It will be her first public appearance since the October slayings.
"She is a strong girl, a girl of faith," Hill said Thursday.
"I believe to come and perform the national anthem, which is this country's favorite song, at a time that our country is stepping up and moving forward for future generations - I think it's just the perfect choice."
Hudson did not participate in Thursday's NFL news conference introducing the game entertainment. Hill, who is singing America the Beautiful, appeared with pre-game act John Legend. Bruce Springsteen and the E Street Band appeared separately to discuss their participation in the halftime show.
Hudson, who had released her self-titled debut album shortly before the killings, is also scheduled to sing at next week's Grammys' MusiCares event in Los Angeles. She is nominated for four awards at the February 8 Grammy Awards.
Hudson's 57-year-old mother, Darnell Hudson Donerson; 29-year-old brother Jason Hudson; and 7-year-old nephew Julian King were slain in Chicago in October. Her estranged brother-in-law has been charged in the killings.
Hudson won an Oscar for best supporting actress for her role in Dreamgirls.
"I have not spoken to Jennifer, but there has not been a day that's gone by that she has not been in my family's prayers," Hill said.
