Actually . . . I know I've seen eyes for stuffed animals that are the "pearl button" type, where the top of the button is a half-dome with an iris and pupil, and on the back is a loop to sew the eye into the toy so that the fabric around the eye hides the loop. So maybe that third eye is that style of button! 
I also like the idea of the third eye being a button all right, but when you look away, the pupil moves, and when you look back it's a a "hey, wait a minute!" moment. It'd be most effective if the Abbie were pretending to be just a stuffed toy.
I also like the idea of the third eye being a button all right, but when you look away, the pupil moves, and when you look back it's a a "hey, wait a minute!" moment. It'd be most effective if the Abbie were pretending to be just a stuffed toy.
