You seem pretty spot on with Spirited Young Lady.
Rebellious Princess seems to be more about the princess not wanting to fulfill their royal duties, whether that be a political marriage, or being the paragon of purity their father wants them to be.
There is definitely some overlap but the Rebellious Princess is much more about trying to avoid their obligations than just bending the rules of what is expected of a woman in the time period.
Ah, yeah, that definitely sounds like a better way to describe Rebellious Princess. The examples under Spirited Young Lady make it seem like a period-exclusive trope, but it doesn't seem like there's anything that makes it explicitly so.
I'm starting to think the comparisons on those pages could stand to be revised. I might look into that.
The pages for Rebellious Princess and Spirited Young Lady link to each other, but all either really says is that Spirited Young Lady is lower on the social hierarchy.
Reading through, I get the impression that a Spirited Young Lady would be someone who is overall content with her social status, engages in some eyebrow-raising behaviors, but generally stops short of anything that would cause a major scandal.
Then the Rebellious Princess either wishes she wasn't nobility, or behaves with absolutely no regard to her title. Also she tends to be more likely to subvert class expectations instead of just gender expectations.
Or am I wildly off base? Either way, it seems like there ought to be more difference than just one being higher-ranking - right?