Should she warn the professor to say nothing to Fred?
It might turn Fred against Marion to know what she had done; Fred was so queer and old-fashioned about women.

Still, he would be sure to hear of it somehow, and it might be best to tell him herself, as tactfully as possible, because she knew so well just how best to approach Fred.
She told Fred and was amazed at the result.
"Well, what of it ?" Fred demanded with brotherly bluntness.

"It takes a woman, by thunder, to knife her friends in the back.

What are you trying to build up anyway?
Take it from me, old girl, you want to cut out this picking away at Marion behind her back--or to her face, either, for that matter.

You two women are going to see a good deal of each other between now and spring, and you'll be ready to claw each other's eyes out if you don't shut them to a lot you don't like." "Well, upon my word! I was merely telling you of Marion's adventure.
I'm not saying--" "No, but you're thinking, and you want to quit it." Whereupon Fred went off to his tent and indulged in a much needed siesta.
Kate was angry as well as hurt.