Jennifer Hudson tried to put the ordeal of the last three weeks behind her as she spent the day relaxing with her fiancé.
A friend told the Chicago Sun Times, "This was one of the few moments of pure fun Jennifer has had in a long time."
Accompanying Jennifer was her sister, Julia, the ex-wife of William Balfour, who was found guilty Friday of murdering Jennifer's mother, brother and seven-year-old nephew.
The friend said the day out was, "A way for Jennifer, her sister and David to blow off some steam and release the horrible tension they've been dealing with for so many months."
Mother-of-one, Jacinta Gholston, was one of the jurors who convicted Balfour after a three-week trial.
Gholston told INSIDE EDITION, "I'm very happy for her. That she was able to go out and celebrate and have fun. To have gone through something this devastating to her family, I can only imagine the relief that she felt after hearing the verdict."
She said Jennifer's daily presence in the courtroom did not influence the jury's verdict.
"This case was not the Jennifer Hudson case. This case was the state of Illinois against William Balfour," said Gholston.
Jennifer said in a statement, "We want to extend a prayer from the Hudson family to the Balfour family. We have all suffered terrible loss in this tragedy."
Jennifer and her fiancé, who already have a son, are reportedly planning to have more children.
Despite the cheerfulness on display at Six Flags, Mother's Day was said by a family source to have been a difficult time for Jennifer.
"Mother's Day is always going to be tough for her," the friend said.