Karen's Witch (Baby-Sitters Little Sister #1)

Is she Mrs. Porter...or a witch? Karen lives next door to an old lady named Mrs. Porter. Mrs. Porter wears long black robes and has wild gray hair. Her black cat is named Midnight. No wonder Karen thinks Mrs. Porter is a witch! Mrs. Porter is having a meeting at her house. Karen is sure the meeting is for witches. Are the witches going to cast a spell on Karen? Or will she be brave enough to send them away-once and for all?