I know myself that Bianca is not a Hot. But Bianca is a good friend of Jill's who lives with the Preps. If it wasn't for Cathy Cluck, Jill would have been at the Preps' party for sure. After all, she does live there. Since Jill doesn't get along with the girls from HOT, in order not to be alone, she would have invited a good friend. Bianca. Bianca tells her father Geoff about it and he starts to look for Bianca. But at the Cathy Cluck it happens, Jill cancels Bianca at short notice and she does not go to the preps party without Jill. Geoff didn't know about this and is now looking for his daughter Bianca.
This is just a theory I developed because Geoff's ring is the same as the ring from the guy next to Amelia at the concert. I don't think Geoff is Jill's father, but he is sitting right behind Bianca, who also has red hair.
It doesn't have to be, but it could be.