Mark 14:67

And when she saw Peter warming himself
At the life which was in the midst of the hall:

she looked upon him;
very earnestly, knowing him to be the same, she had let in at the motion of one, that was known in the high priest's family; and suspecting him, by being a stranger, and by his looks:

and said, and thou also wast with Jesus of Nazareth;
that is, one of his disciples; (See Gill on Matthew 26:69).