So these are just my theories so far, and I need to yap about them, don't tell me if I'm wrong I'll find out if I am.
Theories
1. Lottie is a witch trying to bring the antichrist into the world. When Lottie suggest the baby shower she says "We should do something to welcome him" and when Shauna questions her about it she corrects it to she, she has demonstrated occult powers and seems to be trying to get as close to Shauna as possible to get her trust and she gives Shauna a blanket with the symbol on it. In literature about witchcraft it is often said that witches try to bring about the antichrist through a pregnant women, intending to create a perverse, evil imitation of the birth of Christ.
2. Tai's sleepwalking stuff is Lottie using the devil to possess her for nefarious purposes.
3. Lotties commune is secretly a satanic cult, self explanatory.
If y'all want to discuss your own theories and are past season 2 please create a separate forum topic.