Joy Simon, 61, was attacked on Monday morning in an office at Winterton Community Academy near Scunthorpe.
The girl, who cannot be named for legal reasons, did not enter a plea when she appeared at Grimsby Youth Court.
She was remanded in custody until Friday when she is due to appear at Hull Crown Court.
The teenager, who is also charged with carrying a blade on school premises, stood in the glass-fronted dock and only spoke to confirm her name and personal details during the 20-minute hearing.
While she was being led from the dock, the girl waved at her parents, who were also in court. They blew her a kiss and she returned the gesture.
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