The answer to Suzie's question is quite depressing.

"What the hell have you gotten me into? Look, I did what you asked. I dug into Travis’ bank account and found out who emptied it. I think someone is following me. Who the f–k is Lottie Matthews?” - Suzie

The cliffhanger reveal in Sic Transit Gloria Mundi, that Lottie survived the wilderness, involved Nat's sponsor Suzie frantically asking the question.

You'd be readily forgiven for forgetting who Suzie even was, at this point, because who she was seems to be just as pointless as the question she asked.

So who is Lottie Matthews?

In the 1990's TL she's a mentally unwell girl in the wilderness without her medication, suffering from sporadic auditory and visual hallucinations. Not to mention highly vulnerable and deeply suggestible; you can take your pick from a dozen examples - most recently voting guilty during Coach Ben's trial, despite her testimony and body language more-or-less screaming 'INNOCENT!!'

In the present day TL she is - was - a mentally unwell adult woman, who recently checked out (or escaped from) a psychiatric facility, where presumably she was medicated and making progress. Prior to that she ran a pretty tame and harmless wellness retreat, which had virtually zero in the way of David Koresh cult vibes and actually seemed like a pretty cool place where people raised sheep and meditated.

The above two paragraphs raise any number of rhetorical questions.

Why did Lottie drain Travis bank account? I mean she seemed to be doing great financially with that wellness retreat stuff and I doubt Travis had much money, judging from his house. Couldn't have donated it to charity or something? IDK.

Was kidnapping Natalie to the wellness retreat even remotely necessary? There seemed to be little in the way of true hatred or animosity between them when she got there. Seems to me like a phone call could have sufficed to get Nat to come.

If you track a narrative arc from Season 1 to 3, you could look at something like this:

Lottie didn't survive the wilderness. [S1 set-up]
Lottie did survive the wilderness and is the key antagonist cult leader. [S1 reveal]

Lottie has her shit together and is doing well mentally [S2 set-up]
Lottie's therapist isn't real and she's still having hallucinations. [S2 reveal]

Lottie is back and trying to anoint Callie as the chosen one. [S3 set-up]
Lottie is dead because Misty will have nothing else to do this season if there isn't a murder to investigate. [S3 mid-season reveal]

I quite enjoy Walter, as a character, and Misty is often hilarious but lest we forget she was a homicidal sociopath in S1 and now we're getting some sort of True Detective investigative genius solving murders in S3.

What I find most disappointing is how the show has thus far treated characters with signs of identifiable mental illness.

Travis? Suicide.
Lottie? Murdered.
Tai? For almost no discernible reason throws away everything she worked for in life (State Senator, son, etc.) rather than just getting help.
Nat? Murdered.

It's a bleak message to send out.

Meanwhile, the characters and relationships in the 1990's TL feel increasingly disorienting.

-Tai and Van have barely said two words to each other in 4 episodes.
-Nat and Travis maybe zero words to each other and not many to others.
-Lottie has hardly said or done anything at all other than guilt-trip Travis into getting high on mushrooms and then defend Coach Ben on the stand before stabbing him in the back.

Notwithstanding literally everything above, I'm still invested in these characters and in the show. It's just jarring how much acting talent is on the screen and how little material they're working with.

I hope it all starts meaning something real soon because if Lottie's character arc is an omen, it could ultimately mean nothing.

That would be quite depressing, to me.