Quote 1
"Summon all our people to meet me here as speedily as they can. Call out the giants and the werewolves and the spirits of those trees who are on our side. Call the Ghouls, and the Boggles, the Ogres and the Minotaurs. Call the Cruels, the Hags, the Spectres, and the people of the Toadstools. We will fight." (13.16)
As the head of the forces of Evil, the White Witch isn't playing a lone hand. There are many different types of creatures in Narnia that follow her, and she merely acts as their captain. Evil is not an isolated incident in this world – it's a major dimension of things and wields a great deal of power.
Quote 2
"You have a traitor there, Aslan," said the Witch. Of course everyone present knew that she meant Edmund. But Edmund had got past thinking about himself after all he'd been through and after the talk he'd had that morning. He just went on looking at Aslan. It didn't seem to matter what the Witch said. (13.37)
Edmund's conversation with Aslan dispels all the after-effects of his betrayal. Edmund has begun to change radically and forever, and part of that change is that he's not thinking about himself all the time.
Quote 3
"You know that every traitor belongs to me as my lawful prey and that for every treachery I have a right to a kill." (13.41)
The existence of betrayal in Narnia is what gives the Witch a basis for her power.
Quote 4
The Witch was just turning away with a look of fierce joy on her face when she stopped and said,
"But how do I know this promise will be kept?"
"Wow!" roared Aslan half rising from his throne; and his great mouth opened wider and wider and the roar grew louder and louder, and the Witch, after staring for a moment with her lips wide apart, picked up her skirts and fairly ran for her life. (13.54-56)
Because the White Witch is herself a treacherous creature, she assumes that Aslan will try to trick her if he can. Of course, we know he would never do anything like that – and he doesn't. It's not in his nature.
Quote 5
"Tell you?" said the Witch, her voice growing suddenly shriller. "Tell you what is written on that very Table of Stone which stands beside us? Tell you what is written in letters deep as a spear is long on the trunk of the World Ash Tree? Tell you what is engraved on the sceptre of the Emperor-Beyond-the-Sea? You at least know the magic which the Emperor put into Narnia at the very beginning. You know that every traitor belongs to me as my lawful prey and that for every treachery I have a right to a kill." (13.41)
Narnia isn't all beautiful landscapes and feel-good romps with Aslan. There are painful requirements in the spiritual laws of this world, and the country itself could be destroyed if Aslan didn't abide by those rules.
Quote 6
"It is a lovely place, my house," said the Queen. "I am sure you would like it. There are whole rooms full of Turkish Delight, and what's more, I have no children of my own. I want a nice boy whom I could bring up as a Prince and who would be King of Narnia when I am gone." (4.26)
The Witch's barrenness – her inability to generate her own offspring and become a mother – is part of her evil. She is not a functioning element in a family group, but a dangerous outlier.
Quote 7
"Oh, but if I took you there now," said she, "I shouldn't see your brother and your sisters. I very much want to know your charming relations. You are to be the Prince and – later on – the King; that is understood. But you must have courtiers and nobles. I will make your brother a Duke and your sisters Duchesses."
"There's nothing special about them," said Edmund. (4.28-29)
The Witch may only be using them as an excuse, but it's interesting that, even in the tale she uses to trick Edmund into working for her, family represents an important point of appeal. In contrast, Edmund is already willing to cast off his siblings in order to ally himself with her.
Quote 8
She got him to tell her that he had one brother and two sisters, and that one of his sisters had already been in Narnia and had met a Faun there, and that no one except himself and his brother and sisters knew anything about Narnia. She seemed especially interested in the fact that there were four of them, and kept on coming back to it. "You are sure there are just four of you?" she asked. "Two Sons of Adam and two Daughters of Eve, neither more nor less?" (4.20)
Both the local construction of the Pevensie family – four children, two boys and two girls – and their historical genealogy – descendants of Adam and Eve – makes them the perfect group to fulfill ancient Narnian prophecies about the destruction of the Witch.