Nelly grew up in an affluent family, who believed that everyone was equal, and those who were lucky enough to have more than they needed should do what they could to help those less fortunate. Her clan were all honest, hard-working, moral people, and they greatly influenced her development. They all felt a strong sense of spirituality, and were active in the local church. By the time she entered her teenage years (a few years after the Battle of Triscot, when here clan went into hiding), she became a spirit-talker. In part this was to help her deal with the isolation she felt because of her clan's circumstances, but also it was because she felt there was nothing more important than God. She eventually developed a theory that not everything in the O'Gas should be regarded as true, including the supposed fact that God Himself had sometimes appeared to spirit-talkers over the years.
In the years after her clan came out of hiding, her own philosophical writings (though none were published in the O'Gas) became popular, and she eventually became a teacher at Triscot University. The school of thought she began, which some call Nellianism, held that God is nothing without faith, and faith is impossible in the absence of doubt. Since no one on The Land had ever had reason to doubt God's existence, Nelly reasoned that God must allow spirits to convey untrue information to spirit-talkers, and it is therefore up to every individual to determine which things to believe and which to disbelieve.