Screen time for babies

These few days my mil been really keen to let my 2.5 mth old baby watch nursery rhymes on youtube to assist his learning and also to occupy his waking hours. There's once he watched for about 2 hours in between feeds while me and my hubby was out. I've told her nicely that it's best to cut down screen time and talk/play more to baby but she did not take it very well. She say its better than letting baby 'gong gong' lie on the sofa or go to sleep. But the thing is I'm having my maternity leave now so I spent a lot of time with baby teaching and training his motor skills and not just let him idle away. Any advise? Same thing for drinking water, she insist of letting baby drink some when he's difficult to calm down. She went to the extend of getting second opinion from her younger brother and his wife even though we told her that it's strictly advised by the Paediatrician not to give.