Note I wrote Puerto Rican ethnicity. She's a New Yorker to the bone, born and raised there. But she will use some Spanish words (and I don't discard using some PR slang, but something very basic). Imagine an argument between Alexia and Nia.
For us, Spaniards, there are some changes (so a lot of chances to fuck up with the slang):
Puñeta: Fuck!
Hacer la puñeta: Messing up with someone
Mandar a hacer puñetas: Sending someone to hell
Corrillo (with double R) can be the same meaning as your Corillo
Al garete: Doing something so badly that it failed spectacularly (Mandar al garete)
Chévere isn't used here, but it's understood.
Pon and Cojer monga aren't used here.
She will be the less surprised of the new girls.