>CR = Party Level
>Use Low Attack and Low Damage column for her melee attacks, but grant AC one CR higher than normal
>Primary attack DC should use the High column, +2
>Completely immobile.
>DR/Adamantine based on CR (5 for 1-5, 10 for 6-10, 15 for 11-16, 20 for 17-19, 30 for 20)
>Three main attacks:
>Fire Wave (Burst centered on her, 1d6 Fire per HD, Reflex half, blocked by obstacles). Place columns in the room for PCs to take cover behind.
>Shockwave (She hits the ground. 30' or so Cone, 1d6 per 2 HD, Fortitude vs. Prone, success no Prone and half damage. Cone knocks down columns onto PCs for minor (1d6-3d6) damage and Pinned, Reflex to avoid entirely)
>Maddening Gas (Cloud of noxious vapors in a 10' radius Emanation somewhere within 60', causes Confusion on a failed Will save, Success causes Shaken instead, persists for 3 rounds, new save each round to shake it off, no extra saves allowed if you end turn in the cloud, lasts for 2d4 rounds after exiting regardless of saves)
>She isn't alone in the room, single monster encounters suck.
>Holes in the walls with Small constructs. Very fast, move in pairs, wimpy on their own (CR + PC level - 4), 4 of them total, make them creepy mechanical children that run on all fours, Claw+Claw+Bite full attack with Pounce and a Climb speed, immune to her special attacks, generally try to flank PCs that get caught in the fumes or pinned under a column.
>2 Large Honor Guards. High AC, High to-hit, High damage, DR/Adamantine, modest HP, no special attacks, immune to her special attacks, but 5' land speed. Reach weapon with Trip attempt on success. Stand near the Lady at all times, try to keep the PCs away.
Look at the faces.