Duchess Cadence of the Northlands.
 
Cutie Mark has a meaning and alternate interpretation.  
Because her biggest interest is the well-being of her crystal subjects, her Mark is now an even bigger Crystal Heart, which represents her all-consuming bond with it. She’s their watchful guardian, like a loving mother.  
Her Mark can now also be interpreted as a “frozen” heart: as an almost full time Cupid, while bringing ponies together, she has little to no time for romance in her own life, thus making her an “Ice Queen” of sorts, for all of the good reasons.
 
She’s known to keep Windigos away from her people. But that’s because she actually owns them. She tames them.  
And that’s a double-edged sword. The only reason the windigos haven’t consumed their owner yet is because of the strong ties she has to her ponies - because she refuses to let herself become hateful.
 
Hate means nothing to her.  
To her enemies, she’s the cold indifference.