S.P.
Ah . . . from such imagination are poets made.
The older girls will probably be engineers or teachers or attorneys.
This one will be a poet or an artist or a composer.
She also sounds very very smart.
Comfort her, love her, let her know you'll always keep her safe.
Some of the moms here will probably suggest
some "go away monster" solutions . . .
a spray bottle with water, maybe a little spice or other fragrance.
Spray liberally around the room with ritual language
indicating that this is a safe, monster-free area.
Let us know what happens.