Where is Willow Blue's invitation?

Spoilers for Willow Blue's death below

Usually when a character dies in The Sexy Brutale, their invitation can be picked up off their corpse. However, I haven't been able to find an invitation for the psychic Willow Blue.

Willow Blue dies at 7:00 after she hangs herself off a bell. While there's no way to reach her body once she has died, Willow gives a possible hint to the invitation's location at 2:15:

Now, back to the tank... I think I dropped my invitation...

This led me to believe that Willow's invitation might be by the fish tank in the secret ritual chamber hidden in the painting room. However, I haven't been able to find the invitation despite my best efforts.

Where can I find Willow Blue's invitation? Is it by the tank?

Solution 1:

After you've gotten Willow Blue’s mask ability, go back to the tank while she's not there and talk to the fish in the tank.