Reading skills (Redo)

In my book L.A candy the two bestfriends move into there new place, when JAne talks about her friend always brinign home guy friends she tells us tehy can never find their way back to her room and always end up kncking on the wrong door. My question is that when Jane is talking about her best friend she calls her Scarlett. BUt then when the guys yell her name trying to find her they call her Cassandra. So does scarlett give them the wrong name. Is there more than two people leaving in the house, like is there three friends and not two. Or is scarlett maybe a nickname that Jane has called her forever because it says thatt they have been bestfriends for a long time. I know i have had a few friedns that i have been bestfriedns with for a long time, but like them you would never know what the neckname meant because its nothing like their real name and thast how me and my friends are. ALso once i read a book called Aquamarin and they named her and they just kind if made up the girls name because she was a mermaid and she didnt have a name so they called her aquamarine and it didnt reallly have a purposse they just kind of made it up si its like how Jane made up her name Scarlett and her real name isnt scarlett and this grils wasnt aquamarine. Also in this book They move to LA and my aunts bestfriend , Marie moved to LA 2 years ago to start a fashion line and work with fashion just like jane and scarlett moved there for the high end fashion.