Here's more on what Angel Valley offers:
Angel Valley offers a variety of energy healing modalities, approaching a imbalance from different angles. Each angle approaches the whole from a different entrance. This entrance can be through the muscles, meridians, the chakras or the subtle energy bodies. Ultimately each entrance has an effect on the whole system. It is our experience that using more than one modality often brings the most optimal results. Therefore our practitioners will often combine modalities within a session.
Aura Healing balances our physical body with the surrounding more subtle energy bodies, together called the aura. The aura reflects the state of being: the state of the union between the various aspects of us.
Colon Therapy is the process of flushing large amounts of water into the intestinal track to help release toxins. This cleansing may be supported by a recommended diet to heal from serious disorders.
Crystal Healing allows the healer to work with powerful crystal tools, which, when used with intent and intuitive guidance, can induce and magnify healing energies.
Dolphin Energy Healing is a modality in which the practitioner channels the energies of Dolphin consciousness which brings joy, peace, love and healing energies.
Browsing the Angel Valley website, I don't see many claims about Native beliefs or practices. Which is good, because these New Agers aren't directly stealing Native culture. But also bad, because they have no business allowing a Native-style sweat lodge on their land.
Here's what appears to be the Hamiltons' only claim to "Native" expertise:
Amayra is the co-founder of Angel Valley. She moved from Holland to Sedona in 1997. Her journey into spiritual awareness took off in the early 1980’s when she began her study of spiritual psychotherapy. She learned color therapy and chakra balancing. She expanded this work to the use of essential oils, massage and body/energy work. Amayra also works with crystal skulls, with the Mayan Calendar and Mayan Signatures. She is an artist and loves to use art and creativity to heal herself and to help others to heal.
Hamilton probably chose Maya beliefs to appropriate because she thinks the Maya are mystic guardians of the universe, or something. Because she thinks their beliefs are cool, catchy, and marketable. Because she thinks the Maya are dead and gone, or at least far away, so they won't contradict her.
For more on the subject, see Owners Speak on Sweat Lodge Tragedy, Ray Retreats from Tweets and How Sweat Lodges Can Kill.