If she expects you to do all the work, however, that may be a bit much. One thing I have always required of my players is that they bear the majority of the research / creative load should they want to play a character whose cultural explorations are meant to figure into the campaign in a prominent fashion. That said, read everything you can on sweat lodges and other Native American shamanic traditions. As far as whether the experience is real, leave that to the individual players to decide for their characters.
“In our every deliberation, we must consider the impact of our decisions on the next seven generations.”
-- Great Law of the Iroquois Confederacy