Lexi made a face at Blossom at the mention of there being no courage left in Gryffindor. 'Course there was courage left, enough to last them at least seven years. She didn't even flinch as Rico did his little freak-out, which was entertaining, she had to admit; and she found herself laughing.
"Rico, why don't you walk in front of me," she said. "Then you can warn us if there are any ghosts or monsters waiting for us." With this, Lexi put her hands on his back and pushed him down the dim corridor, "What? All talk and no action Slytherin? You coming?"
The jab at Slytherin was purely in good fun, just to defend her pride and get back at the Gryffindor comment a while ago.