Stick to the principles of Reiki, and don't interfere with the religion or beliefs of others, and step into service with love. Allow yourself to LET GO, and let the Reiki energy do the rest. Allow the magic into your life and become one with the Source. The more you let go, the more it will flow. Age is no barrier with Reiki.
Infants benefit from the attunement and it starts their life on a path of service.
Senior members of society benefit from being able to heal themselves, and others. Reiki is not only for those that want to heal others, it is for everybody. Being attuned to be Source brings wholeness.