Wiccans, being pagans, do have deities, although they don’t have a central doctrine about the nature of these deities. What you need to impress upon your daughter is that while her friend and her parents may be doing the best they can and may be trying to honor the good as they see the good, we Christians only worship the one true God. You might read her this section of Acts to give her an idea about how St. Paul went about interactions with pagans of good intention:
“You Athenians, I see that in every respect you are very religious. For as I walked around looking carefully at your shrines, I even discovered an altar inscribed, ‘To an Unknown God.’ What therefore you unknowingly worship, I proclaim to you. The God who made the world and all that is in it, the Lord of heaven and earth, does not dwell in sanctuaries made by human hands, nor is he served by human hands because he needs anything. Rather it is he who gives to everyone life and breath and everything. He made from one the whole human race to dwell on the entire surface of the earth, and he fixed the ordered seasons and the boundaries of their regions, so that people might seek God, even perhaps grope for him and find him, though indeed he is not far from any one of us. For ‘In him we live and move and have our being,’ as even some of your poets have said, ‘For we too are his offspring.’ Since therefore we are the offspring of God, we ought not to think that the divinity is like an image fashioned from gold, silver, or stone by human art and imagination. God has overlooked the times of ignorance, but now he demands that all people everywhere repent because he has established a day on which he will ‘judge the world with justice’ through a man he has appointed, and he has provided confirmation for all by raising him from the dead.” When they heard about resurrection of the dead, some began to scoff, but others said, “We should like to hear you on this some other time.” And so Paul left them. But some did join him, and became believers. Among them were Dionysius, a member of the Court of the Areopagus, a woman named Damaris, and others with them. Acts 17:22-34
In other words, nothing the Wiccans are saying is anything new that the Apostles didn’t know about.
Mostly, though, the way with Wiccans is to be virtuous and life-giving, to be a picture of the grace of Christ, rather than full of creed, which they will resist.
Now who is going to harm you if you are enthusiastic for what is good? But even if you should suffer because of righteousness, blessed are you. Do not be afraid or terrified with fear of them, but sanctify Christ as Lord in your hearts. Always be ready to give an explanation to anyone who asks you for a reason for your hope, but do it with gentleness and reverence, keeping your conscience clear, so that, when you are maligned, those who defame your good conduct in Christ may themselves be put to shame. For it is better to suffer for doing good, if that be the will of God, than for doing evil. 1 Pet. 3:13-17