The appearance comes amid a return to the music industry for the 'Irresistible' singer.
Jessica Simpson kept it spicy as she stepped out to celebrate the 66th GRAMMY Awards on Sunday with her sister, Ashlee Simpson Ross, and brother-in-law, Evan Ross, at Steven Tyler's Jam for Janie viewing party in Los Angeles.
The 43-year-old singer and fashion mogul stunned in a red hot number, opting for a figure-hugging floor length dress that included an open neckline with long lace sleeves. She accessorized with a large cross necklace, talon fingernails and sparkly rings, while wearing her blonde hair in loose waves and glamming it up with dark smokey eye makeup.
Ashlee looked elegantly goth-glam, wearing an all-black long sleeved gown and slicking her auburn hair up in a chic bun. She kept her makeup simple with a clean cat eye, but dressed up her digits with pointy nails and several rings. Her husband, Evan, appeared perfectly coordinated in a long black jacket by Saint Laurent.
The trio enjoyed their night out in support of Janie's Fund, presented by Live Nation, at the Hollywood Palladium. The fifth annual event -- which was co-chaired by Ashlee and Evan and hosted by Zooey Deschanel -- featured a live performance by The Black Crowes. Janie's Fund serves to support girls and young women healing from the trauma of abuse and neglect.
Meanwhile, host Deschanel made it a date night with her fiancé, Jonathan Scott.
Jessica's latest appearance comes amid her return to the music industry. Back in November, the star made her first red carpet appearance since 2018 -- when she was pregnant with her youngest child. The artist shares three children with her husband -- daughter Maxwell, 11; son Ace, 10; and daughter Birdie, 4.
"Music is very exciting for me right now because I have just finished writing, so now I'm about to record it," she recently told ET. "My kids will be introduced to me as an artist, and that is the most powerful part about it -- to see them see me as, like, what my childhood dreams were. To watch me, as a woman, walk on stage as their mother, and be that for them. I'm very excited about that part."