My 3 year old daughter is addicted to watching cartoons/ toddler programs on YouTube. She's gained the intelligence to even unlock my phone and remembers my passcode very well. How do I get her to lose interest? I usually give in to her during meal times as I want her to finish the food.

Different kids has different ways to tackle. If you have already used this method to make sure she finishes her food, it may be tough but still able to change this habit. She may start off with crying as you have interrupted her routine but you are left with no choice. You have to be firm and ensure that this habit is kicked off. You may wish to do it slowly like from 30 mins reduced to 15 mins, then to 10 mins, then to 5 mins and eventually 3x a week, once a week, etc ... In this way, the changes are not so fast and difficult for the kids to adapt.