The Pearl Harbour actress was all smiles as she posed for the cameras in London on Sunday evening (22 November), during her first public appearance since allegations about her marriage surfaced.
Several outlets noted that she was not wearing a wedding ring.
Rumours about Kate's marriage to filmmaker Len surfaced over the weekend, with a source telling People magazine in the US: "They are still friendly and spend time together in L.A. when Kate is there. There is no drama."
Kate and Len, both 42, have not confirmed if the claims are true.
British-born Kate and director Len married at the Bel Air Hotel in Los Angeles in May 2004, with Kate's daughter Lily, then five, acting as bridesmaid. Lily's father is Kate's ex-partner Michael Sheen.