Why is Sune Chaotic Good?

[Luccan]

This isn't 5e specific, though it comes from playing 5e. AFAICT, Sune has always been CG.

When my new group was brainstorming PCs for our IceWind Dale game, I'd considered making a Light Cleric and, not wanting to be absorbed in the sea of Lathander clerics, settled on Sune as a sort of out there choice for both an adventuring cleric and a dwarf cleric. But from what I can gather after some research, Sune cares about pretty things, pretty people, and outward displays of love more than any genuine feelings beyond physical attraction. She doesn't seem concerned with much else and rejects the less aesthetically pleasant outright. So why is she Chaotic Good, of all alignments? This seems like a particularly Neutral attitude, on the Good-Evil axis.

I could be missing information that hasn't circulated online, but given she's based on late 20th century perception of Aphrodite, it's hard to imagine there's much more to say. So why is Sune CG instead of CN or some other form of Neutral?

Edit: The answer is you should read primary sources.