New restrictions include a daily time limit, nighttime blocks and hidden likes.
Facebook and WhatsApp are failing to remove imposter accounts that "have led to tens of thousands of dollars of fraudulent transfers," says Manhattan DA Alvin Bragg.
A jury found Meta and YouTube liable in a lawsuit that aimed to hold social media platforms responsible for harm to children using their services.
Parents interviewed about the verdict said they view the decision as a step toward stronger protections for children.
The woman - identified in court as KGM - is the key plaintiff in the case, which alleges she began using social media as young as age 6 and became dependent on the apps.
Adam Mosseri, the head of Meta's Instagram, testified Wednesday during a landmark social media trial that he disagrees with the idea that people can be clinically addicted to social media platforms.