Karen is informed by owl that she's a prefect. She writes her friends about that, of course.
"Does that mean you won't get along with her? I bet Malfoy will trade me Abbott if you'd sooner not share."
"It was great! We've got more firsties than sixth years, you won't mind an extra, will you?"
"I don't know the family -"
"I'm Muggleborn."
"Ah."
"I'm good in Defense because when I was twelve I had to duel a sixth-year over it. I won."
"- how'd you do that?"
"I cheated. But it's okay, this is Slytherin, and what's important is that everyone knows I could cheat the next time too." She smiles.
"- nice to meet you."
"You said."
Same things minus the Runes and plus Alchemy! She does not find Madam Hirudinea a very useful teacher past the basics and finds herself cleaning more bedpans than she'd like so she's dropped that.
Karen doesn't want to drop anything. Scheduling concerns opt her out of Defense and Runes. She skips Alchemy after much debate.
Miranda loans Fawley a demonstrative stick and her first year Charms notes and wand motion transcriptions for the spells.
She appreciates that! It'll make the studying go better!
The next day is Saturday and she's absent all day. In the evening she goes to her rooms and is asked where she was and says 'my mother said she found a secret passage to Hogsmeade in her day and bet me ten Galleons I couldn't find it inside a month. Once the month's up - or I figure it out, I guess - I'll study with everyone else. But I really want the Galleons, I've almost enough for a broomstick."
"Ooooh," one of her roommates says. "Do we get half if we find it?"
"I don't know about half but you could have a Galleon."
"Deal. Fourth floor, statue of the witch, you say 'dissendium'."
" - brilliant," Fawley says, and does not sleep well.
The next day she asks Miranda if Miranda knows of any ways a first-year could get a Galleon on short notice - "I lost a bet."