Apparently people think Lottie is sad/melancholic in the last episodes of s3 - I really disagree with this, I think there's every indication that she has undergone some kind of spiritual awakening/enlightenment.
We don't know if Lottie heard Shauna say, "You shouldn't be afraid of the dark parts of yourself either" but even if she didn't hear it - I think that's what she was learning from Shauna, and it's what reconnected her to It - culminating in her murdering the outsider, which she viewed as a tribute to it.
When Lottie does this it's almost as if she goes into a trance, and reaches some kind of grand understanding that she had been struggling with before.
We see her echo this sentiment later in the cave.
The loss of her fear is important, because it is what blocked her connection in the first place after she was horrified at what the group did while she was injured.
But now through embracing her dark parts and losing her fear of violence, she is ready to submit to its will again.
Through this, we see Lottie seemingly regain her supernatural abilities.
She walks over the pit trap. They went with a version of this scene that was more subtle, but there was a version where she called Travis pathetic for attempting to kill her. You can still see a flash of annoyance on her face when she hears a branch snap and realizes she is over a trap.
She is able to navigate the cave in darkness, whereas Akilah needs a flashlight to find her (in this specific area there does seem to be a light source overhead, but I think leading up to it is meant to be pitch black).
Her clairvoyance also returns:
She knows that Akilah attempted to trick her into calling for a hunt by poisoning her animals. Knows it was hard for her to do. She calls for the hunt anyways, probably because it's what It wants, and she views it as a proper anointment of Shauna.
A lot of people view Lottie as dressing Shauna up as her god, but I actually disagree with this interpretation. After all, how would Lottie, at the moment this vision occurs, have known that Shauna was going to request Mari's hair and want to be adorned with it?
I believe the ceremony of Shauna being dressed is meant to mirror Nat's coronation - where everyone offers tribute. I don't think the entire outfit was Lottie's idea, but instead a collaborative effort of the team. However even if it was all her design - she would still have had foresight to the fact that Shauna wanted to take Mari's hair as a trophy.
I also disagree with the common interpretation of Lottie's warning to Mari - though it is intentionally dubious. Mari has been there before from falling into the pit before - but I think Lottie was also telling her she had been there before in past lives.
There are inconsistencies with what we saw of pit girl in the pilot and what we got in the s3 finale - and I actually think this is entirely intentional, because what we see in the pilot is a different timeline. We get cuts to it with the odd TV static effect - which is usually how the show edits to imply something supernatural.
When we originally see pit girl's death, we almost sort of see it through the eyes of the wilderness - there are cuts to tree eyes.
When Mari runs off to die, we see Lottie contemplate this.
I believe it's because the Wilderness had already shown her this.
Towards the end Lottie becomes very spacey and in my opinion it's peaceful and meditative - not sad like some people interpret. She has given up attachment and completely submitted to the Wilderness. The Wilderness being like a drug to her makes this a pleasurable experience.
Like sorry but she's a killer now and she's happy about it haha.
I wouldn't have her any other way, personally.<3