Hello, first time I've posted but I think I'm pretty well-versed in the lore and this forum by now.
The important thing to remember about this helper is that she's a sort of religious counselor. If you have forgotten or have not seen an explanation of the oxen story, its concept comes from the Bible. Although I know she is a follower of Thelema, it is not unbelievable for them to use concepts from Christianity, as Thelema is sort of an amalgamation of different religions. There is a passage in 1 Corinthians 7 that explains exactly what Bree is talking about here.
In fact, it is the verse that Christians often use to justify a policy of only being in romantic relationships with those of similar faith. The strength she refers to is strictly her faith, which she clearly has much more of, in the case of Thelema.
My guess is that Bree told the helper about Daniel, and the helper told Bree this story to discourage her from being tempted to be close to him. The helper also probably told Bree the bit about Daniel deciding he wasn't gonna be there for her.
I think pretty much any of the assertions Bree made in this video came directly from the helper, and we shouldn't take them as something Bree would say naturally.
As for what the ceremony is, I think it is not a sacrifice but moreso a sexual magick ritual. I'm thinking something along the lines of a Geisha's virginity being sold to the highest bidder, except without the money.
I did a detailed analysis on the keyword "bastirma" from the "My Difficult Decision" video. Bastirma may be a ruse. If you click on the tag, it brings up
one video in the search(same for phytoplankton, but a different video). The one video for bastirma is called "mulohia", more commonly spelled "molokheya". This is an Egyptian vegetable that is very healthy, and Cleopatra used it as a source of health and beauty. As Crowley was a drug user, I also found that the famous Egyptian narcotic Khat is often smuggled by being labeled molokheya. Khat is also the word for "body" in Egyptian, and I found this reference on a Thelema website in which khat was related to sexual magick.
http://www.ashe-prem.org/five/adams.shtml It says there they worship the body more than the spirit. This ceremony could be a worshipping of Bree's body. The khat smuggling also reveals to me a metaphor that Bree is doing something she thinks is healthy and good(molokheya), when it's really not good(khat).
Well, this last paragraph was just me having fun. I doubt I made connections the writers expected. But the information is useful regardless.
Knowledge is just opinion that you trust enough to act upon.
-Orson Scott Card, Children of the Mind