Jennifer Hudson is fronting a cheerful holiday commercial featured across the U.S. less than a month after the tragic deaths of her mother, brother and nephew.

Hudson's mother Darnell Donerson, and brother, Jason, were found shot dead at their home in Chicago, Illinois on 24 October, three days before her seven-year-old nephew, Julian King, was found dead in an abandoned car after a brutal killing spree.

The main suspect in the case, William Balfour, who was married to the Oscar winner's sister Julia, is still being quizzed by officers over the slayings.

But, in spite of her grief, Hudson has put on a brave face for a new holiday campaign commercial with casual-wear retailer Gap, despite being given the option to back out.

The ad features a smiling photo of the actress, wearing a bright red sweater.

The store giant's spokesperson Olive Doyne tells E! Online, "She said she wanted to be a part of it and that we should move forward."

Balfour lost a bid for freedom on last week after the Illinois Parole Board found "probable cause" for him to remain behind bars until next month.