I’m 100% sure there were at least a few movies with Daphne, Shaggy, Scooby, and scrappy, and there was one series with Vincent price. But I could be conflating them, I’m kinda drunk
It looks like I may be wrong, and they may have changed her appearance and voice actors in some of the shows. I guess that's why I didn't recognize her.
You're dead on, it's episode 8, When you witch upon a star. About 12 minutes in. I didn't know this off hand, I spent 20 minutes scrubbing through the episodes.