Katy Manning (in-universe)

A cloaked figure once surveyed images of the Doctor's friends and companions, with one of them depicting a blonde woman posing nude with a Grey Dalek. (COMIC: Unnatural Selection)

When Simon encountered a older version of the he was travelling with that he didn't immediately recognise, he thought that she had the look  "someone famous". (PROSE: Enter Wildthyme)

Behind the scenes
Whether the blonde woman is supposed to be Jo Grant or an in-universe Katy Manning is ultimately unclear, but since the image is an almost 1:1 of the same infamous photo of Katy Manning posing nude, it is more likely to be the latter.

Additionally, the blurbs for Iris Wildthyme and the Celestial Omnibus and the charity anthology Bafflement and Devotion: Iris at the Edges describes Iris Wildthyme as looking like the "spitting image" or the "alter-ego" of Katy Manning.

Katy Manning also played "herself" in The Five(ish) Doctors Reboot.