I had some trouble with Priya too. It seems that after she deferred to Ashok and sent Deepa to India so that they could manage better financially, she kind of distanced herself from really caring for her children.
She worried that Deepa was putting herself in danger with the protests, but shrugged it off. She thought Maya was her model child and even when she suspected trouble over the expensive necklace, she shrugged that off too - very willing to believe that Deepa (who denigrated expensive things - especially when needed to impress rich white people) would have just spent her own money to help Maya do just that. And then, of course, knowing that Ajay needed help, she just let that go as well.
She was very quick to accept Archie's judgment that she had done everything she could for her kids - that Deepa was just headstrong, Maya was deceptive etc. However, to her credit, she also finally accepted Archie's insistence that Ajay needed help. (But if it hadn't been for the police incident, I'm not sure she would have.)
She also was very quick to believe that if they had just stayed in their previous neighborhood, everything would have been fine (and that moving back was the way to fix everything.) I'm not so sure that's true. Deepa is more angry than ever. And will Maya really be willing to give up the privilege she aspired to and saw within her grasp? And what is the future for Ashok now that his dreams were shattered? At least there may be hope for Ajay.