Lady's Whisper can choose whether or not it counts as undead for effects that affect undead differently. Even if it does not count as undead, Lady's Whisper never counts as a living creature.
Constant Spells
A constant spell affects the monster without the monster needing to cast it, and its duration is unlimited. If a constant spell gets counteracted, the monster can reactivate it by spending the normal spellcasting actions the spell requires.
AC 31; Fort +18, Ref +20, Will +25; +1 status to all saves vs. magic
HP 195, void healing; Immunities bleed, death effects, disease, paralyzed, poison, unconscious
+1 Status to All Saves vs. Magic
Negative Recovery
Lady's Whisper can choose whether or not it takes vitality damage.
20 feet. Each creature that begins its turn within the aura and can hear the ominous whispers must succeed at a DC 30 Will save or become Frightened 2. On a success, the creature is temporarily immune for 1 minute.
Lady's Whisper mentally causes any doors or portals within the Gate of Nhimbaloth (areas B60 to B64 and areas C1 through C18) to open or shut. If Lady's Whisper wills a door closed, it must be Forced Open or battered down.
Unwilling Teleportation(divine, teleportation)
When Lady's Whisper hits and damages a creature with its claw Strike, it can choose to teleport that creature to any open space within 15 feet, even if Lady's Whisper can't see the destination. The target can attempt a DC 30 Will saving throw to resist this effect.