The couple, who are trying to make their relationship work, were snapped at their son Jett's first birthday party yesterday (17 August).
Although they are living under the same roof and welcomed a baby girl earlier this month, Katie and Kieran have not been publicly seen together since news of his infidelity broke more than three months ago.
Yesterday, however, Katie and Kieran were all smiles as they celebrated Jett reaching his first milestone while surrounded by their family and friends.
In the photo, mum-of-five Katie can be seen smiling as Kieran holds their son in his arms. Uploading it to her You Gossip site, she said: "Capturing the moment."
Katie also posted a snap of Jett's birthday cake, which she told fans was made by Kieran's mum. "Jett's birthday cake how amazing :) made by Nanny Hayler xxx," she said.
On 4 August, Katie's rep confirmed she had given birth to a baby girl and it was later revealed Kieran was present and had held her hand during labour.
Since then, Katie has shared the first photograph of their daughter and described her as "daddy's little girl".
On May 7, Katie announced that she would be divorcing Kieran after discovering he'd been having a seven-month affair with her best friend, Jane Pountney.
Both Jane and Kieran have since apologised for their actions and Katie has decided to work at her marriage before giving up completely.
During her Fubar Radio show recently, Katie confirmed that Kieran is receiving therapy for a sex addiction and has been working hard to change his ways.