Jessica Simpson joined sister Ashlee, her boyfriend Pete Wentz and mom Tina for a lunch at El Torito in Encino, California, US reports.

This was her first outing since being hospitalized with a kidney infection

"Jessica was walking very slowly with her hand on her back. You could see she was in a little bit of pain," an eyewitness told US. "She was dressed down and trying to stay low key."

During the lunch, "Jessica picked at a salad and didn't eat much — but she was in good spirits and was laughing very loudly with her sister," the witness added.