My daughter is 14. We will get her a mobile phone next year. She has an iPad and a laptop. She has issues with youtube shorts taking attention away from school

My daughter is 14. We will get her a mobile phone next year. She has an iPad and a laptop. She has issues with youtube shorts taking attention away from school work on her laptop. We will be maintaining screentime controls, and won't allow TikTok to be installed on her phone. She has a snapchat account, and uses it primarily for the messaging feature. She knows she's not allowed to view content not related to her friends and we regularly check up on that. We have the password to both her devices. Since we discovered she has problems with impulse control with YouTube shorts, she can't have her door closed if she has her computer or iPad in the room with her. She is an avid reader, and reads for hours a day, re-reads the same books, and on YouTube she mostly consumes recipes, book reviews and book related content (like fanfic) so by most standards she's pretty good. That being said, once she has a phone, she will not be allowed to use it in the house at all. Our youngest has fewer issues with impulse control, and uses her iPad for things like Duolingo, Toca Life and Finch the self-care pet and messaging friends on iMessage or Facebook Messenger kids. She doesn't have access to YouTube, but does have YT kids. She likes the tiny cakes channel and regularly brings me the videos because I find them very enjoyable also. They're both very heavily supervised and when they demonstrate there are problems, we take away their devices. My eldest has had an apple watch SE since year 7 and we use that for communicating, and she can get in touch with friends that way. I also bought a 4g nokia with has the SIM for the same number in it (I had to use my backup iPhone to set up her watch) and if she is going somewhere further or longer than a school day she takes that for safety reasons. My youngest will follow the same trajectory, we talk about the risks with them often, and they aren't allowed phones at school (by the school) and have had regular online safety sessions provided by the school. Australia is also seriously considering legislation to criminalise allowing children under 16 from having any social media accounts. Note that we only got them iPads in 2020 because of home schooling, prior to that we had given them iPhone 5s each to listen to podcasts and music. We always used screentime controls, and had them set up with family sharing and their own iCloud accounts, they have never (even as children) been allowed to use either mine or my wife's phones, we never let them watch or listen to anything during dinner or on car rides under 2 hours (a rule that still stands).