A.T. Robertson Commentary Mark 14:67

"and seeing Peter warming himself, she looked upon him, and saith, Thou also wast with the Nazarene, [even] Jesus." — Mark 14:67 (ASV)

Warming himself (θερμαινομενον). Mark mentions this fact about Peter twice (14:54,67) as does John (John 18:18,25). He was twice beside the fire. It is quite difficult to relate clearly the three denials as told in the Four Gospels. Each time several may have joined in, both maids and men.

The Nazarene (του Ναζαρηνου). In Mt 26:69 it is "the Galilean." A number were probably speaking, one saying one thing, another another.