Star Royalty

Okay, so at the beginning of Star Wars, Leia, is "Princess Leia" a
senator.
In the prequels, Amidala is queen. then, she's not queen, someone else
is queen, that right there presents a problem, apparently in his
universe Lucas has decided that royalty works differently, he doesn't
explain it, it's just different. which then leads us back to the
question, if Amidala had Leia, and Leia is adopted by Senator Organna,
then how is she a princess? She could be a princess if the Organna
family was royalty, not a hard jump to make, a barren royal couple
decides to adopt the dying queen's daughter, thus insuring that if not
of the same blood line of the organna's , it would in fact be a more
direct/pure blood line when she accends to princess, and eventually
queen.

But then maybe I've put more thought into this in twenty minutes than
George Lucas has in twenty plus years.