Let Mavis go obviously. She's a good, innocent vampire. Only a monster would let her get killed and hurt her family like that.
If it was that Scream Queen bitch from Scare Tactics (where this bit is originally from) however, let her fry. She and her ilk were killing and feeding on people but got all indignant when the village people finally caught them. Wanna act like a wild animal? Fine, get treated like one.