Is the Guilty Crown(Cat's Cradle) that Yuzuriha Inori offers Ouma Shu Jacob's Ladder?
Yes, the string figure Inori offers is 4-step Jacob's Ladder.
In Japan, the hobby is known as ayatori. Also, in ayatori term, the string figure Inori offers is called hashigo (ladder), specifically 4-dan hashigo (4-step ladders).