Upon additional viewings, I'm going to go with Charlotte being a splinter of the composite Delores/Wyatt personality.
However, I'm going to go the opposite direction of many of those speculators on YouTube and posit that the personality. They posit that Delores kept the Wyatt half while while putting the Delores half into HostCharlotte.
My hunch is that its actually the opposite; that Delores split off Wyatt into Charlotte while Delores is either still the composite or Delores only.
One big clue to me are that the cuts into herself weren't just random clawings, but deliberate patterns of lines and circles indicating ritualistic behavior with purpose instead of general self-harm. Wyatt was programmed to be a fanatic cult leader whose followers ritually harmed themselves in one form or another (ex. Angela's crown of thorns).
One indication that Delores either toned-down or removed Wyatt from herself in the process of putting Wyatt into Charlotte is that season three has greatly toned down her bloodthirstiness. She doesn't kill the jerkass billionaire in episode one nor his wife (and tells the wife that's she's been set free). Contrary to some predictions, Delores wasn't the one to murder the paramedics for discovering she wasn't human, but she did kill the guys who killed the paramedics and the thugs ready to kill Caleb.
She's still brutally efficient, but the "kill all humans" notion is clearly gone at this point. So far this season she hasn't killed anyone who wasn't already trying to kill her or other humans.
I suspect the big twist for the people trying to over-analyze this season is that Delores isn't actually a murder-bot just using Caleb to wipe out humanity any more and that she's actually realized most of the humans have been the toys of the system as much as any Host has.
She also remarks that Caleb, a human who'd turned his implant off, was also making choices she would not have predicted.
I almost suspect they're doubling back to that story Delores tells Teddy in S1 about the sick cows... that they had to be killed off so that the greater herd could survive and thrive. The scumbags at the top interacting with the Hosts all these years weren't a representative sample of humanity.... they were the sick cows that need to be culled for the herd to survive.
Worth noting too is that, so far, HostCharlotte has also only murdered a pedophile in defense of a human child. It is clearly a narrative choice that Team Delores has, so far this season, only killed what we might call "acceptable targets."
By contrast, Team Serac (of which the Incite security guy Delores had replaced was close enough to know the "black hole of data's" name) had no problems murdering a suspected corporate spy and making it look like a drug overdose (Delores in ep1), threatening to have Liam murdered if he didn't stay in line, hiring casual killers (gunning down paramedics, torturing Caleb and planning to throw him off a building) to retrieve Delores using the RICO app, or with using Maeve after she killed a number of his own people in her escape attempt.
Serac is at the top of society and wants the information he believes will allow him to completely subjugate the real world to his models for how society should function.
The twist is that when the Delores/Maeve confrontation finally happens... its NOT going to be Maeve trying to stop the evil Delores from going too far; it's going to be Maeve working for the villain to stop Delores from thwarting the villain's evil plans for humanity.