I agree with your daughter and strongly urge you not to contact this person. I know it's tempting, but believe me, nothing good will come of it.
Why do I say this? One reason is because many who claim to have occult powers actually are frauds; they're only interested in your money. But others are in league with demonic spiritual powers that are opposed to God, which could cause you serious spiritual harm. The Bible commands us to stay away from any type of occult activity, including sorcery, the casting of spells, and spiritism. The Bible warns, "Anyone who does these things is detestable to the Lord" (Deuteronomy 18:12).
But the other reason I urge you not to go down this path is because you don't need to! If your mother knew Christ, she is safely in heaven, and all the struggles and pains she had on earth are over -- forever! In heaven, the Bible says, God "will wipe every tear from their eyes. There will be no more death or mourning or crying or pain, for the old order of things has passed away" (Revelation 21:4).
The real question you need to ask yourself, however, is this: Do you know for sure that you will go to heaven when you die? You can be sure, by turning to Jesus Christ in repentance and faith, and trusting Him alone for your salvation. Commit your life to Him today.