So this is just information and based on the new song TryHardNinja uploaded to YT about Alice, I instantly made a direct connection to Harmony, and he even states in the description that sees Alice having three split personalities.
And throughout my RPs and Harmony's origins, I've hinted at something being completely wrong with Sabrina..

Most of the time she can be sweet and loving,which is normal
The other part if evil and gluttonous, just like Zara
But if you read through her origins again and see how she acts when she's alone and by herself there is another side to her: Depressed and Devious

Now, I won't go in depth about her normal self or into Zara.

But let's talk about this third personality.

In her origins when her birthday was over, Harmony was dragged down to the basement by her uncle (who was in a constant state of depression and rage over what happened to his daughter, the only person he really cared about) and chained up in a cell. Only to be beaten and abused, and in between, she'd try to attack Henrick. It's been going on since she was 11. Haley was the first to discover this, and helped Sabrina escaped. Even her old psychiatrist noticed this.

And this is true:
Harmony doesn't even think she's beautiful, and she isn't Perfect..
She still has her extra mouths, but they're disguised as scars in their place.

She will do anything to make herself Perfect. No matter at any cost.