Instance in which Harvey is turned into a dog by one of Sabrina's cousins, Amanda (played by Melissa Joan Hart's real life sister Emily)
Both Brian Cousins (Emil) and Hallie Todd (Marigold) have been in Star Trek: The Next Generation. Cousins plays the Borg Croesus and Todd plays Lal, the daughter of android, Data.
Marigold's magic manifests itself as red sparkles outlining the object she's casting a spell on, combined with a red shimmer from bottom to top. She also doesn't cast magic through pointing, instead holding her hand out with an open palm.
Amanda and Ally's magic manifests itself as steam of sparkles that continues to change colors as the sparkles appear.