In the book: Because Pearl and her mom are nomads, one would think that they'd both be keen to the ways of the world. But even though (or because) they move around a lot, Pearl remains naive about a lot of things. The lack of stability in her life drives her straight into the seemingly comforting arms of the Richardsons, which begins to change her. However, it takes a while for that to drive a wedge between Pearl and Mia, and even when that happens, their bond is still strong.
On the show: Pearl's innocence is apparent, and she's painfully incognizant and/or tolerant of the Richardsons' microaggressions toward her. On top of that, she seems more enwrapped in Mia and Elena's tug of war. She and Mia get into some heated arguments that are admittedly very emotional and pull at the heartstrings, but their fracture happens very quickly on the show, and it's more intense. Seeing them become distant that rapidly makes you wonder if they were close because of their healthy relationship or because they were all they had. In comparison to Ng's text, Pearl and Mia's solidarity feels shakier.