Princess Leia Organa has no one to belong to.
Perhaps on paper, but not in the way her culture measures family.
It is true that adoption and fosterage is not unknown on Alderaan, even in the most prominent of families. Rather, it is an old and valued tradition, as respected as the monarchy itself.
As the members of the monarchy serve as symbols of the virtues and responsibilities upheld by each kin-group of Alderaan, and the lives of the royals (carefully written down, and learned by every Alderaanian child of a certain age) embody the tradition and history and courage of their people, the practice of fosterage reminds all of the value of adaptation and acceptance.
It links kin-groups together, borrows threads from another's history to weave into the tapestry of scéal dhírshinsear, the ancestor-tales, that every child learns at their mother's knee. (Or godmother's, or grandmother's, or aunt's.)
Leia Organa has no scéal dhírshinsear to bring to her father's house. She does not know the tale of her birth, and even the names of her ancestors go unremebered. Even the names of her parents are unknown to her, and she burns with the shame of it whenever her too-sharp ears catch the whispers of ill-mannered courtiers.
The whispers start softly: Prince Bail was too grieving, too desperate, too kind.
Fosterage is an old and valued tradition, and veil of secrecy surrounding the Princess's adoption shames the practice. She is a royal (or pretends to be) and her history belongs to all the people, they murmur.
Leia Organa is no child of Alderaan, they say.
Each overheard rumor is a knife in her heart.
The more intelligent murmur that Leia Organa was perhaps a child of the Jedi, rescued from the creché near the night of the rebellion.
Something must have happened to the children of the Jedi, after all, and it is likely that the youngest ones were returned to their families or else quietly adopted, their records erased. Under such circumstances, it is possible that Prince Organa did not know the parents.
It is a kinder thoery, and Leia wishes she could believe it.
She spends months trying to, weeks and weeks trying to remember what it must have been like in the Temple creché. After the fifth nightmare of blood and blue light and slaughter, her nurse tells her to stop thinking about it.
She has a family, she knows. (Leia doesn't realize her thoughts drift into the present tense, when she only intends to be searching for her past.)
But her feelings tell her that she had a mother, and a family, and history enough to bring honor to the House of Organa. And without that knowledge- knowledge that is as much a part of her identity as the shape of her nose or the size of her hands- she will forever be missing a piece of herself.
As long as she is missing a piece of herself, she will never fully belong in any kin-group.
Still, Princess Leia is as honest and forthright as any of the Royal House can be, in the days of the Empire.
She defends her people in the Senate, and upholds the dignity and honor of the planet of Alderaan. Despite her clouded beginnings, many of the less tradition-bound expect that she will be a good Queen, someday. If she seems to fight all the more fiercely because she knows what she is missing- well, drive can be an asset in a monarch.
Meeting Luke Skywalker does not, in fact, heal the soul-rending agony of having her planet vaporized.
Princess Leia Organa has nowhere to belong to.
(Perhaps -in time- on paper, but not in the way her heart measures home.)