Hysterics won’t help, but I see no indication that the OP is already “deep into the hysterical zone.” Talk about overstatement.

Back to the OP, forbidding her at this age could very well push her into rebellion on the issue. Hopefully she has a solid grounding her her Catholic faith. I might try to find a way to reiterate Catholic beliefs when it comes to topics of divination or seeking ways to control nature through magic, and why Catholics do not do such things, and why God is the focal point of our lives who has created the wonderful natural world around us. This may require re-educating yourself or a refresher on your part. I’d try to frame it in a positive way about this is why we believe and why without making it sound like you’re calling her friend or her friend’s family “evil” or anything along those lines. Maybe try to broach the issue without even bringing her friend up at all. You don’t just want to forbid your daughter, you want her to be comfortable and knowledgeable about what she believes.

What is meant by “wiccan” varies. I had a wiccan acquaintance in high school who thought he was a poltergeist who could make things happen or fall off walls when he was angry. Others might be more serious about nature worship, others might be basically agnostic/atheist and just like and respect nature. So I’d be careful about assuming what this family actually practices and just let your daughter know more about her own faith.