In the snapshot, Simpson's one-year-old son with Eric Johnson can be seen playing with Rocco on the floor with an adorned blanket.
Simpson and Johnson welcomed Ace in June 2013 after three years of dating. The two were already parents to a daughter, Maxwell, who was born in May 2012. The proud parents tied the knot earlier this month in a 250-guest wedding at San Ysidro Ranch in Santa Barbara, Calif.
Days after her wedding Simpson hinted that she'd be taking her husband's name by sharing a bikini photos of herself titled, "Jessica Johnson."