You can short rest in her lair but not long, and fast travel is now also restricted in her lair.

Now if they just implement a consequence of some kind for leaving and resting and coming back, then it would make perfect sense.

Still, the lair is one of the hardest in the game. I guess, though, they really let you know. The door now even tells you. RUUUN!!!!

Like the old Dexter's Lab cartoon, "Enter at your own peril, past the vaulted door..." 😁