as much as possible and instead doing real stuff in the real world.
Social media is really detrimental to them, whether cell phones or laptops. Just because Facebook lets them create accounts at 13 years old doesn't mean it's a good idea—it's an arbitrary age, not based on research. If we were really basing it on research, we'd probably not use social media until their frontal lobes develop in their mid 20s. More realistically ... just delay as long as you can.