Happy,
I know that you desire to do the right thing. But seriously, you need to remove yourself from her completely, also not to call her. Each time you do this she feeds into you. And you are allowing her to do so. You have not let her go completely either.
And yes, you are correct that God is greater than witchcraft. However God does not expect us to be foolish in not taking percautions when it comes to people who are into witchcraft. In the OT God states to not have anything to do with witchcraft at all. To stay far from it. And if this woman is dealing in witchcraft than you need to stay far away from her until she gets deliverance.
Another thing, the spirit realm is nothing to mess with. Nor should anyone challenge Satan or anyone who delves into witchcraft or any form of it. Also the fruits are to be showing in this woman's life and the church and if you do not see the fruit of the spirit operating than you are in the wrong spot. If you are not familiar with what the fruit of the spirit is than you need to read Galations 5:19-26
"The acts of the sinful nature are obvious: sexual immorality,http://www.biblestudytools.com/galatians/5.html#cr-descriptionAnchor-32 impurity and debauchery; idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy; drunkenness, orgies, and the like.http://www.biblestudytools.com/galatians/5.html#cr-descriptionAnchor-33 I warn you, as I did before, that those who live like this will not inherit the kingdom of God. But the fruithttp://www.biblestudytools.com/galatians/5.html#cr-descriptionAnchor-35 of the Spirit is love,http://www.biblestudytools.com/galatians/5.html#cr-descriptionAnchor-36 joy, peace,http://www.biblestudytools.com/galatians/5.html#cr-descriptionAnchor-37 patience, kindness, goodness, faithfulness, gentleness and self-control.http://www.biblestudytools.com/galatians/5.html#cr-descriptionAnchor-38 Against such things there is no law. Those who belong to Christ Jesus have crucified the sinful naturehttp://www.biblestudytools.com/galatians/5.html#cr-descriptionAnchor-40 with its passions and desires. Since we live by the Spirit,http://www.biblestudytools.com/galatians/5.html#cr-descriptionAnchor-42 let us keep in step with the Spirit. Let us not become conceited,http://www.biblestudytools.com/galatians/5.html#cr-descriptionAnchor-43 provoking and envying each other."
You mentioned that when the woman prays for you that her eyes turn red and she spits at you. This is demonic. Also anger is coming out at YOU.
I did check the website that you had provided. I see that this is a spanish church. So is the pastor a woman or a man?
Moriah Ruth