There are over a billion Hindus. Are they all demon possessed or witches? There are about half a billion Buddhists. Are they all demon possessed? There are one and a half billion Muslims. Are they all demon possessed?
Every man has the spirit of satan indwelling them automatically.
in which you used to live when you followed the ways of this world and of the ruler of the kingdom of the air, the spirit who is now at work in those who are disobedient. - Ephesians 2:2
It's not a question of whether lost people operate inside the spirits of the devil, and have demons influencing them. Every lost person does to some degree, even if it is just a sin nature. Elijah, for example, had a sin nature (spirit of the power of the air indwelling him). He also yielded to a demonic spirit of fear when he fled from the threats of Jezebel.
Demon possession is different, however. Yes, all men have the evil spirit of air living in them unless they are Christians, but their will power is in control. They can choose to do this or do that. So the influence of demons in their life may not be terrible, or they may be heavily oppressed of the devil but not possessed (Acts 10:38). And there is a range, from someone who is like Elijah or Moses, who they have a sin nature, but they have some relationship with God... down to the Canaanites who had demons living in them and among them.
However, there is demon possession, and this is also to various degrees. At it's worse, a person's entire willpower is overridden, and it is a devil living in a person managing their affairs, while their own willpower is shunted to the side. Now, even when this begins to happen, a person can try to exercise their will and gain control back, but it could be too much for some, such as the man who lived in tombs that Jesus had to save. (Mark 5:3)
Witchcraft is actually a false religious spirit, combined with curses and deception. Now, what makes a person a witch, is basically the realization that their words hold spiritual power as they are spoken. At which point, like this lady's mother, she can curse people, exercise the belief that there is power in those words, and the curse of the devil goes through the spiritual reality to attempt to curse that person.
Whether that person permits the curse upon them is another matter, however. No Christian is obligated to listen, and furthermore, it's highly, highly dangerous to curse Christians who know what they are doing.
When a deceiving spirit began operating through a witch as Paul as preaching, we see the results:
Acts 13
But Elymas the sorcerer (for that is what his name means) opposed them and tried to turn the proconsul from the faith.
"You are a child of the devil and an enemy of everything that is right! You are full of all kinds of deceit and trickery. Will you never stop perverting the right ways of the Lord? Now the hand of the Lord is against you. You are going to be blind for a time, not even able to see the light of the sun." Immediately mist and darkness came over him, and he groped about, seeking someone to lead him by the hand.
And I hope that after that man was blind for a time, he repented and became a Christian just as Paul did.
But you see how when a witch confronts a real Christian using deceit or other things like curses, it backfires? They speak deceit, but rather God defends Paul's ministry, and the sorcerer receives the truth in return for his deceit.
However, her mother who goes cursing people will reap that sin in her life:
He loved to pronounce a curse-- may it come back on him. He found no pleasure in blessing-- may it be far from him. He wore cursing as his garment; it entered into his body like water, into his bones like oil. - Psalm 109:17-18
But you see, even born again Christians need to watch their words. It's very, very important what we speak, because we hold more authority in our words than the kingdom of satan. This is why we should speak life and healing.
