Harry Potter's twin sister

GUYS THIS IS MY FIRST STORY SO I'M NEW TO THIS STORY WRITING THING. I'M FROM CROATIA AND ENGLISH IS MY SECOND LANGUAGE SO SORRY ABOUT ALL THE SPELLING AND GRAMMAR MISTAKES I MAKE. I HOPE YOU LIKE MY STORY. PLEASE LIKE AND COMMENT IF YOU WANT ME TO CONTINUE THE STORY.

Chapter one:

A one year old baby girl was having fun with her family when she heard something very noisy. She heard her dad say "Take Harry and Tina with you! I'm gonna stall him and you run away!". Her mum took her and her brother and started running. She put Tina and her brother in the crib. Tina saw a strange man walking in the room and heard her mother say "Please don't kill Harry and Tina! Kill me instead!". Tina started crying so she couldn't hear anything. She saw a strange man doing somenthing with a stick and her mum falling on the floor. The strange man did something with a stick again and Tina felt pain on her forhead. She thought her head is going to blow up. Then the pain stopped and the strange man dissapeared. Her brother was crying too. She closed her eyes and covered her ears with her hands so she coildn't hear anything. After a few minutes she opened her eyes and saw  a huge man who took Tina and Harry and put them in a strange bike. He got on the bike too and the bike started flying. Tina felt safe in that bike so she fell asleep. The bike flew into a street named Privet drive. There was an old man and a woman younger than the man but still old standing in the middle of the street. The old man said "It would be the best if Tina would come to live with me in Hogwarts where she's safe because I'm going to take care of her and Harry should live with his cousins, the Dursleys, because they're muggles.". Tina was looking at her brother who was still sleeping. She moved her head and  saw that everyone was looking at her and her brother's foreheads. Then the big man asked "Are they going to have those scars for the rest of their lives?" The old man said yes. Then he took her brother and placed him in front of a house in front of them. The big man started crying so the woman started calming him down. The old man took Tina in his arms. Tina was confused because they were in a street with all those people and after 1 second they were in a strange village. Tina saw a big castle. The old man started walking towards the castle. Tina was very tired so she fell asleep. When she woke up it was already morning. A woman Tina never saw before fed her and took care of her. As soon as she got used to the new home she learned that the big man was Rubeus Hagrid, the Keeper of Keys and Grounds of Hogwarts. Then she learned the woman was Minerva McGonnagall, the Transfigurarion teacher and a deputy headmistress. And she also learned that the old man was Albus Percival Wulfric Brian Dumbledore, the headmaster. Tina was happy while living in Hogwarts beacuse everyone took care of her. The students sometimes played with her when they had free periods. Everyone liked her. When she turned seven, Dumbledore called her to his office. Tina was confused and a little scared. Dumbledore told her that she's finally old enough to know how she got that scar on her forehead. Dumbledore didn't tell her because he thought it would be better if Tina and Harry found out some things together. Tina loved walking around the castle and meeting new people. One day, when she was 9,  she saw Percy Weasley yelling at his brothers, Fred and George, because they did something bad. When Tina saw Fred she knew that love in first sight excists. Tina saw an old man named Argus Filch dragging Fred and George in his office. She secretly followed them. She waited quietly to hear something. She heard something exploding. After 5 minutes Fred and George came out with a strange paper. Tina stopped following them and she started walking around the school again. One student (who was on his sixth year) came to her and told her that Dumbledore needs her. Tina went to Dumbledore's office. Dumbledore told her that, if she wants, she can go to some classes to watch what she'll learn when she goes to school here. She nodded and thanked him. She went to professor McGonnagall, told her what Dumbledore told her and asked her if she can come watch her class. Professor McGonnagall nodded. Tina was very happy. She went to some other classes that day including Astronomy, Defence Against the Dark Arts, Herbology,... Time has passed so fast Tina hasn't even realised that tomorrow is her 11th birthday.