William Balfour is charged with murdering Hudson's mother Darnell Donerson, her brother Jason and her nephew Julian King.
Prosecutors say Balfour unleashed his deadly rage after learning Hudson's sister Julia, his estranged wife, was dating another man.
Jennifer Hudson is an Academy Award and Grammy Award-winning superstar.
She's promised to be in the courtroom every day and could take the stand.
Star struck jurors are a concern not only for the defense, but also prosecutors.
"They have to stay focused," said trial lawyer Susan Filan. "They can't resort to any kind of tricks or rest on the fact that they have a star member of the victim's family as part of the prosecution's team.
"I think she's made the personal decision that justice and family support far outweigh any bit of privacy that she would give up to be there for the people she loves," said ABC News consultant Howard Bragman.