While Maya got justice for Claire's murder by killing Joe, she also wants to make sure her mother-in-law pays the price for being complicit in Claire's murder, as well as the damage caused by Burkett Pharmaceutical's dodgy medication. (Inexplicably, Detective Kierce let her go have this confrontation even after finding out Maya had killed Joe, instead of just arresting her.)
To do so, Maya confronts her in-laws at their home with a gun and gets them to confess everything. It's a triumphant moment for Maya, as she turns the tables on her entitled relatives.
Unfortunately, Joe's other brother, Neil (James Northcote), steals Maya's gun and shoots her several times in the chest, killing her.
But Maya has one final surprise: She'd set up a nanny cam livestreaming the whole confrontation to the world via Corey the Whistle. The Burketts effectively confess to all their wrongdoings, and they're left to face the consequences.
In the show's final few minutes, it skips ahead 18 years to show how Maya's daughter, Lily, was raised by her extended family to grow up happy and away from the drama of the past.
She even has a baby girl of her own who she names (you guessed it) Maya. Cute.