From my reading of this article this lady bordered on blaspheme. Christ is NOT in everyone. Of the Pharisees Christ said, "You are of your father the devil, and you want to do the desires of your father." (John 8:44)
Nor is He a needy Christ. He is a Holy Christ. By Him and through Him all things were made not for His needs but for His love. He made all creation with just a word. He will destroy the present corrupted Heaven and Earth with but a word to replace it with a new Heaven and Earth.
This lady
“swore, told off-color jokes, liked gin, and chain-smoked ‘with a dandelion-yellow upper lip.’ And by all accounts, she was a difficult person. She was not patient, kind or gentle.”
You shall know them by their fruit. The fruit of the spirit is love, joy, peace, patience, kindness, goodness, etc. I see nothing to indicate she was redeemed.
C.S. Lewis said once that there was a difference between goodness and good digestion. A person born with good health and a good personality will be loving, patient, etc. because of good digestion: being born with a good personality, yet that person might not be holy since they will be self sufficient and never see their need to repent.
A person born with a bad personality, bad nerves, poor health, a bad temper etc. might daily struggle to be good, and daily or even hourly ask for God's help...they know they need God.
I know nothing about this lady, but if you read carefully, you will see the "fruits" are found in the healing of those around her, and of those who read her books today...
Then it's a good thing for ALL OF US that you don't get to make that determination.