My new Idea

This is just an idea, so please give me all your comments or insults, whichever fits.
Kati
Oh, and should this be a novel or short story?

Kyra could not sleep. She tossed and turned in her bed, until finally she was convinced sleep was not coming. She walked to the window and opened it. A blast of cold, wintry air met her face. Kyra shivered, and looked up at the sky. Silvery stars studded the black night sky. Suddenly, she heard a shrill cry pierce the night's silence. She froze, eyes wide with fear. Then Kyra turned her head to the sleeping body of her sister, Emyael. She stood there for a few minutes; the sound did not return. Finally convinced that nothing serious had happened, the young girl closed the window and went to bed. Her eyelids closed, and did not open until morning.
Kyra was helping Emyael and Tora fix breakfast. "Did you hear it," chattered Tora noisily. She was mixing something together; pancakes, probably. "It scared me so that I jumped clean out of my skin!" Emyael laughed. "Don't be silly, Tora! If anything was to be heard it was just your snoring," she snickered. Tora stomped her foot in protest. "Oh, no it wasn't! It was something else!" The way Tora said the last two words made Kyra's hair stand up on end. There was nothing else to be heard, true, but Tora slept in an entirely different room! And the sound was a cry, not a snore, so Kyra began to say something, but stopped. She had better keep out of this. "There was nothing else to hear except your loud, obnoxious snoring," Emyael snickered again. Tora set the bowl on the nearest shelf and wiped her hands. "Well, for your information, it was not a snore, it sounded very much like a cry, or scream," Tora said. Her teeth were clenched, as well as her fists, a true sign she was unable to hold her temper for much longer. "Oh, did you hear that? Help! It's a dragon!" Emyael laughed and ran around, flailing her arms high in the air. "That's it," Tora said, and she flew at her sister. The laughter soon turned to shrieks and cries from Emyael, and Kyra dashed into the fight. She pulled away and angry Tora and a sobbing Emyael, just as their mother rushed in. "Mama! Mama!" The little one cried, and rushed to her. She tightened her grip on the ruffled skirt and dried her eyes on it also. Tora grumbled something and rolled her eyes. Then she laughed, and expected her older sister to join in. But Kyra stood still, staring into space; she wasn't paying attention. Something was coming; coming toward them. "Hide!" She screamed, terrified. They rushed to the pantry and locked the door, and all was silent. Except for, Kyra thought, the beating of wings.