Young Dorothy is a bit of a homebody. An orphan who's being raised by her aunt and uncle on the gray plains of Kansas, she's used to leading a quiet existence. But when a cyclone picks up her entire house and deposits it—and her, and her little dog, too!—in an unfamiliar land called Oz, her life gets a lot more exciting.
In Oz, Dorothy finds herself chasing around a bunch of flying monkeys and evil witches and hot-air balloons. And you know something? She doesn't need all that drama in her life. All she wants to do is go home. She's not exactly ready for a big adventure, but she's about to get one anyway.
The thing to know about Dorothy is that, wherever she goes, she'd much rather be back in that dilapidated farmhouse with her aunt and uncle. The urbane people of Oz can't quite figure out what she sees in it (and to be fair, Kansas does sound sort of grim), but Dorothy insists there's no place she'd rather be:
The Scarecrow listened carefully, and said, "I cannot understand why you should wish to leave this beautiful country and go back to the dry, gray place you call Kansas."
"That is because you have no brains," answered the girl.
"No matter how dreary and gray our homes are, we people of flesh and blood would rather live there than in any other country, be it ever so beautiful. There is no place like home." (4.6-4.8)
Her heart is back home, but for the moment, her head is in Oz.
Fortunately, she has a good head on her shoulders. From the moment the cyclone lifts Dorothy's house from the ground, she is totally Zen about it. "As the hours passed and nothing terrible happened, she stopped worrying and resolved to wait calmly and see what the future would bring," the narrator tells us (1.19). In fact, she's so calm, she just goes to bed. In a flying house. That's some serious composure.
Oz is a weird and dangerous place, so that Midwestern practicality continues to serve her well on the ground. Dorothy trusts her senses and her intellect enough to accept strange things, which means she's able to quickly adjust. For example, when the good witch disappears into thin air, Toto barks and seems surprised. "But Dorothy, knowing her to be a witch, had expected her to disappear in just that way, and was not surprised in the least" (2.62). Similarly, when the Scarecrow tells her that he can't eat because his mouth is painted on, she "saw at once that this was true, so she only nodded and went on eating her bread" (4.5). She doesn't fuss over him or stare in wonder. She just accepts the strange truth and moves on to the next thing.
Her ability to go with the flow comes in handy on the yellow brick road, where things often go wrong. She seems to make friends wherever she goes, and by the time she reaches the Emerald City, she's traveling with a full complement of odd creatures. Along the way, Dorothy does whatever needs to be done, and she tries to be brave about it. She doesn't let the fact that no one seems to know where the Emerald City is get to her. "She knew that only the great Oz could help her get to Kansas again, so she bravely resolved not to turn back" (3.26). She's on a mission, and that mission is to get the heck out of Oz.
Despite her singular focus on getting home, Dorothy is not exactly a ruthless person. When she lands in Oz—a stranger in a strange land—her first thought isn't for herself, but for her family. "I am anxious to get back to my Aunt and Uncle, for I am sure they will worry about me," she tells the good witch (2.39).
Her tender heart is also on display when her friends are hurt or in danger, which is often. (Oz is crazy dangerous!) She cares about the Scarecrow, the Tin Woodman, and the Lion deeply. Heck, she even cares about her enemies. When she kills the Wicked Witch of the West, she apologizes. That may not seem so odd until you remember that same witch just (kinda-sorta) murdered two of her friends and enslaved both Dorothy and the Lion.
Dorothy may feel bad about having killed two wicked witches, but the fact remains they are dead. To what degree she is personally responsible seems unclear. She has "never killed anything willingly," but the people in Oz certainly seem to give her credit for it (11.60). In fact, Dorothy is dangerously naive about her own power throughout most of the book.
Early on, when one of the Munchkins refers to her sorcery, "Dorothy did not know what to say to this, for…she knew very well she was only an ordinary little girl who had come by the chance of a cyclone into a strange land" (3.23). But ordinary little girls don't normally kill wicked witches, do they? Her naiveté carries through all the way to the delicate china country, where she and her friends, not realizing their own power, are careless and break several items.
At the end of the book, when Dorothy learns she can use the silver shoes to go home to Kansas, she finally comes to terms with her own power. It's nothing new; she just feels empowered to use the silver shoes she always had. The thing about Dorothy—and you'll see this echoed in the characters of her good friends the Scarecrow, the Tin Woodman, and the Lion—is that she never really changes along the course of her journey down the yellow brick road. But journeys aren't always about transformation. This one, anyway, was about discovering something she already had.