Or use her own socks. They sure are smelly, too.
Get some strong duck tape and cut 3 10cm strips off. Then slap them on her face. She wont be able to talk or breathe out of her mouth.
Remove your dirty, stinky, sweaty socks and shove them in her mouth.
What the !@#$ is wrong with you?! You want to gag a girl. You are a big, stupid, idiot!