The week had been exhausting. No one in this stupid castle would have been able to understand how she felt. Alone, lost, betrayed, abandoned. Good Lord why had her father taken that decision?! Going to Hogwarts! She wasn’t a wizard, a witch or whatever. She was an Elemental! She didn’t need a stupid stick -sorry, a wand- to do magic. She could understand the reason her father had taken this decision but… it was tough. Very tough. Apart of the castle and its countless corridors and stairs she was feeling lost because of the people. It was another culture she had never learnt about, not really, and yes, she was very bad with a wand. She was feeling like a fish outside his bowl. Well this first week had been like hell.
And to complete the scene she was right now trying to escape Peeves. That bloody ghost! She didn’t really want to use her power but she felt she would. Professor Dumbledore wanted her to try using her wizardry but she had contained herself to much for not using her real magic, the Elemental one. Tired and irritated she turned round and tried to open the door. The door was locked. As she heard Peeves coming after her she gripped her hand in front of the lock and suddenly loosened it. A draught escaped her hand and unlocked the door. Quickly she jumped into the room, closed the door and sighed. She was safe. And alone. Well, actually not alone. Quite surprise to find someone in this room, Sienna apologized.

« Oh! I.. I’m sorry. I didn’t want to bother you. I.. ‘m going to find another room. Sorry. » She said again about to open the door.

Sadly she was right. The room wasn’t empty. A girl, - Sienna frowned trying to remember which colour (sorry I'm too British in the spelling ) to which house* (it works like that)-, a Hufflepuff apparently, was there reading a book. Who the hell would like to read a book locked in a dungeon? Was she a prisoner? You’re stupid Sienna sometimes, too much imagination a little voice said in her mind. Of course she wasn’t a prisoner! What an idea!!!
Almost immediately she has apologized the girl asked her how she did open the door. Oosh! Brutal! Surprised Sienna first opened her mouth then closed it. She hesitated between answering the question or being as rude as the girl, who ('who' is spot on for a person 'which' really is for objects and things only) realizing her rudeness apologized too.

Sienna shrugged and made a step into the room.
« That’s okay. » She was feeling alone lonely enough to take the liberty of arguing with another student. Slowly she sighed, while screaming like a loony, Peeves passed in their corridor. I will find you!!! Sienna closed her eyes to clam (pretty sure you wanted to type 'calm' ) herself. Hopefully Thankfully the girl seemed to understand the situation and welcomed Sienna to stay. A bit relieved she stepped in (she need to step somewhere).
« Thank you very much. This… poltergeist is a nightmare! »

Gently she came to sit near Elina but probably because she came from a war zone and was completely lost in that new culture she was a bit suspicious and so sat not didn't sit too close.

« Nice to meet you. I’m Sienna Blackriver. And… yes… » She smiled. Oh well!!! Her entrance had been ignored by someone? « I am that new-no-witchy-girl-coming-from-that-distant-country where there is a Dark Lord situation… » Yeah! Good résumé… She remembered her entrance at the Sorting Ceremony. She has arrived hours before the Hogwarts Express bring brought the students… She remembered how she felt had felt waiting in that huge castle alone… And how Professor Dumbledore introduced had introduced her that night. « Owing to troubles in her home a new student is joining us for this year. I ask you to show her all the courtesy and sympathy we use everyday to each other in any circumstances. And please, Gryffindor don’t be too joyful winning a new member in your house. » And after that the diner has had arrived. Till this day Sienna tried had tried to escape the questions. Of course she had to explain to her house why and how she was here and for that she would ever thank Lily Evans for being so nice and protective with her. Anyway, right now in front of Elina, Sienna was quite surprised the girl didn’t know who she was… So it is was (you started with the past tense so it's off finishing with the present tense) silently she waited for questions…



* or maybe best to say « which color represented which house »
** I wanted to say « which one » but for a person is who right? Not very sure about how these two sentences link…