Claudine

‘Another old friend of yours?’ Collier asked politely.
Willie shook his head. ‘Bedfellow,’ he said simply. ‘Nice and friendly with it, though. Une petite amie, as the French say. They’ve got a way of putting things.’
Later she is described as a girl in her middle twenties, with red hair and a small round face. It is to her flat that Willie and Modesty take René Vaubois to force a stand-off with the assassins.
(I, Lucifer, chapter 2)