So, which of the Royal Sisters channeled which Element of Harmony?

[PoisonClaw 8,173]

Each of the Mane 6 channelled a single Element of Harmony, but prior to them, Celestia and Luna wielded the six together. And while Celestia was able to wield all six at once, their power were likely to have been greatly diminished, which is why Nightmare Moon was only banished rather than purified back into Luna. 

 

So, assuming each sister got three elements apiece rather than all six at once, who got what?

 

I'm thinking Celestia wielded Magic, Generosity and Kindness, while Luna channelled Loyalty, Laughter and Honesty. When Luna became Nightmare Moon, her connection to would have snapped like a dry twig.  

[Will Guide 21,371]

The answer is right there in the flashbacks shown in Season 4's premiere. In the flashback of the Sisters sealing Discord the first time, you can see the 6 Elements gems being shared by the two sisters

 

 

Celestia's got Magic, Kindness, and Generousity. Luna's got Laughter, Honesty, and Loyalty.