In what way does Simone demonstrate a growing confidence around Josh in Chapter 11?

In Chapter 11, Abdel-Fattah makes it clear that Simone is becoming more comfortable in her own skin around Josh. Whereas in a previous scene, Simone had immediately stopped being funny and gregarious when Josh entered the room, this time her demeanor is different. When Josh comes walking up to Simone and Amal in the hall, Simone is briefly shy, but then she opens up again and ends up making Josh laugh uproariously with imitations of her mother's materialistic ways.