This is a tough one and the blow back from Anne might include her cutting you out of her life.
A little over a decade ago I was involved in a religious cult and I completely bought into it hook, line, and sinker. For the first year I showed positive results, impressing my family, friends, and other members in my religious community with my "special zeal" for my religion. In the second year, life took a turn. Everything that was good was soured, everything that was bad was even worse. My parents were constantly upset with me and started to worry about me.
About 22 months into my experience, I traveled home and my parents decided to stage an intervention where they listed their complaints. I don't remember the details aside from a generic "You've been uncharacteristically disrespectful." However, what did stand out was my dad telling me that they think I've been brainwashed and that they didn't want me to return to the cult. I dismissed that claim. I felt that it was nearly impossible to be brainwashed and it's only done by sinister people with ill intentions (Nazis, KGB, etc). My cult had nothing but the best of intentions for me, or so I thought. I felt incredulous at their accusations of me and my organization. After our discussion we decided that I should return back to the cult because I was also going to college (on the side). Long story "short" I ended up leaving a month and a half later.
What got me to leave was a perfect storm. Before the intervention I started noticing the negatives in my life. Most of my support group within the cult left and I was feeling listless. However, everything was pretty subconscious so I didn't put enough thought into my situation. Then a couple of weeks after my parents confronted me, it finally hit me that I was wasting my time. I wasn't growing any, despite the numerous promises that I would. I left at the end of the year.
I think that Anne probably needs to have some cynicism, which gets squelched in these kinds of programs (I too participated in a LifeSpring-like convention). For these programs to be considered effective there has to be a suspension of skepticism so that participants "can fully take advantage" of the lessons to be learned. Then, if one session goes well, whether there are breakthroughs or there's that high, then participant can determine that program is right for them. For them the buy-in is that much bigger.
It would probably be best to approach Anne when she's "in a valley." When it's been some time since her last involvement and her high has worn off. Approach her and explain your concerns. Remind her that you are her friend and that you support her. Bring into question if these sessions are actually worth the money. One of my mom's criticisms was that my cult was $8k a year and my returns were definitely coming up short.
Perhaps there's been some good, don't throw the baby out with the bathwater as they say. Maybe she can take these breakthroughs and go through therapy, presumably much cheaper. Hopefully she'll come to realize that the appeal for these kinds of things is not the breakthroughs but the highs. Breaking through is just an added bonus.
Things to Remember
You will not convince Anne of anything. She'll be stubborn and set. She'll believe that what she's doing is perfectly healthy and that she's totally in the right. Part of that stems from our refusal to believe that we can be duped into scams/cults/etc. We know that it happens, but we always think it'll never happen to us. The goal here is to put a bug in Anne's ear so that she starts doubting, so that she starts looking at her situation in a different light.
If she's like me she might have some negative thoughts about the organization subconsciously. My parents were pretty much the catalyst to pull me out. You could be too, but the key is to keep things light. Don't come off preachy and let Anne come to the conclusions that she's in trouble herself.
Like I said in the beginning, Anne might cut you out of her life. She may get so offended at what you have to say that she may deem you as toxic. She has a support group in this organization, as misguided as it may be, and Anne might realize that you don't mean much to her anymore. Outsiders just can't understand how good the organization is and should be ignored.
Try your best to not hold these actions against her. They come from a place of fear and if you, her friend, are scary, then she might feel that she'll have to get rid of what's scary. In the future, when she's wised up, hopefully she'll make amends. Humans are capable of doing crazy things when they drink the koolaid. It makes recovery all the much easier when friends and family are welcoming and supportive when we finally realize our mistakes.