Definitely AI. One of her dozens of Reddit profiles contained images of a completely different AI construct if you managed to dig deep enough. The particular "woman" in these old reddit posts is
Vanessa.Luna, which is also another AI creation. Can't find these posts anymore because they've either been deleted or the accounts containing them were banned.
Funnily enough, I recall seeing a completely different woman digging deep into one of Vanessa's Reddit profiles before it got banned. I wonder how deep this rabbit hole goes.
Whoever is creating these "women" must be experimenting with their own AI model. Vanessa for example looks plausibly real until you see videos where all the obvious AI tells become apparent (idk why they all spline the camera in the same way, but I digress).
Ellie appears to be a 2nd version of their AI model. AI explains the numerous accounts. I believe Vanessa had a similar history of multiple accounts/different names. There is also a half truth behind the explanation Ellie provided of "testing engagement". The other half is more accounts = more backups in the event one gets banned.
And I mean come on, her currently active Reddit profile is called "blondiewhoschubby." This was clearly meant to be a profile used for Vanessa. Nowhere in the history of Ellie's bits of data has she ever been blonde.
Furthermore, real people tend to stick to a particular naming convention when it comes to their usernames. Some common denominator is shared across all of them, in a majority of cases. Every social media name this "person" has used is completely totally different.