Annoying cousin help?

My cousin is living in my house the whole summer it seems like it I need some help from you guys. She (cousin) is 8 years old and she lives here now because her family decided to move here from russia (uncle married a russian) and they have their house being build but they came at the wrong time and their family can't live with my grandma and grandpa for now because my grandma is really sick and you know really young people are germ spreaders so they had to live her because we are the closet. Before she came here I thought she was a quiet little girl. She's been here a long time and I'm really getting annoyed. She is so immature for her age and she cries so much. (Example: She cried last night cuz she couldn't remember her webkinz password. She's been here know for more than a month now and she is just too anoying. It's been so annoying pretty much everything she says or does annoys me a ton. I'm lucky im getting on the computer now cuz she's always on it playing webkinz and while she plays webkinz she makes these really annoying giggles and singing and just stupid noises. When she's not on the computer or the T.V (watching 4 year shows would watch when I was 4) she pretends she a cat and runs around the house mewoing and being really annoying. Another example I just thought of: She gets really angety and cries when things do go her way. I have to spwnt most of my day with her and my only time i'm alone is when she wakes up at 8am and goes to swim pratice. She won't ever be quiet even if we tell her too and I'm not the only person in my family who's annoyed by her. My sister hates her more than me. What should I do to make her less anoying? PS she doesn't ever want to go to the pool right now and she's crying on the floor.