My super cheesy way. LVL 4 STR based dual wielding thief Solo'ed her before she made it through her fireplace. Jumped onto outer deck from outside, stealthed in applied wyvern poison to warhammers. Backstab surprise (with 96% chance to hit), both hammers hit, then both offhand bonus attacks hit all applying 7D6 poison. After first round she is down from 130 something to 30ish HP's. Triggers convo where she banishes girl to cage in basement and starts combat as hag. I go first, jump behind her and backstab again and finish her off.
