(Photo credit: Jamie McCarthy/Getty Images)

Jessica Simpson recently celebrated the impending birth of her son, but last weekend she turned the focus to her daughter, Maxwell.

On Sunday afternoon, Simpson, 31, and her fiancé Eric Johnson, 33, threw a carnival-themed birthday party for their little girl, who will turn one on May 1. Fifty friends and family members flocked to the couple's Hidden Hills, Calif., home for the backyard party, which boasted face-painting and a children's band, along with toddler-friendly foods, including hot dogs and grilled cheeses.

"It was tons of fun for kids and grownups," says an insider. "[And] the food was great."

Meanwhile, Simpson, who has said that this pregnancy hasn't been easy ("I just feel awful," she told Jimmy Kimmel last month), got decked out for the occasion, wearing a dress and wedges. Adds the source: "She had a great time."