It featured three tops with her and her two daughters’ names on them and then a babygro on the end with the name “newbie” on the back.
Zissman simply captioned the photo, posted on Thursday 8 June: “👑💕👶🏼 #girlgang” with a baby emoji.
Zissman is mum to Dixie, six, from a previous relationship, and 10-month-old Indigo Esme Collins, with husband Andrew Collins.
Many fans sent messages of congratulations to the star.
“Great news,” one person wrote. “And not long after baby Indigo - they will be the best of friends.”
Another wrote: “Congrats! Not a big age gap between you and the little one, just like me.”
Zissman announced in August 2016 she had given birth to her first child with Collins.
Zissman shared a photo on Twitter of her newborn’s hand and revealed her name: Indigo Esme.
Congrats to the couple!