I [17M] have a excessive fear of my little sister [6] being influenced by others

First of all, I know that from the title, I may not exactly fit the common definition of "parent", but I'd say that I have a considerable impact and authority over my sister. I definitely love her like a daughter, and my parents are usually busy with their lives and can really only just do the basics, feeding, washing etc. I'm in charge of playing with her and teaching her about a lot of things. Since I'm younger and more tech-savvy, I'm also in charge of online safety, restrictions that stuff. I love everything about her, her unique charming personality, her sense of humour, and she is interested in a lot of cool things like drawing and space. The shows and videos she watches are pretty decent too, which I think has a part to play in her development. This is also important because some of the shows are actually good enough for me to share common interest and engage with her on things that make her happy, thus making us closer (e.g. Bluey, the 2010s My Little Pony). I wouldn't trade her identity for anything in the world.

And that's what's been worrying me so much, because some of her friends watch these loud, stimulating brainrot slop videos designed to grab attention, and just shout out their names a decent chunk of the time. Sometimes the ads on the games she plays has them. I know kids do dumb stuff, we had our stupid internet memes when I was like 9 (not 5 OR 6, I THINK THAT SEEMS LIKE AN ISSUE), but I'm worried that in this age of mass-produced content designed to grab and shrivel children's attention spans, she could eventually just become a mind-numbed iPad kid with no hobbies, or the parts of her identity that make us love her. We do control what she watches, but I worry about when she's a bit older and we'd have to make her a bit more independent, as well as the possibility that she could be left out or influenced by peer pressure. I have anxious attatchment in general, and find it hard to trust the people I love the most, and I know that by being stricter and stricter, constantly nagging her on what she's doing, our relationship would tear apart. I know I might be worrying too much, but I just don't know what to do. I know she hasn't done anything to break my trust, but I worry about what she could really be like when I'm not there, and I don't want to be constantly supervising. Like what if I'm worrying about is already kind of happening? I know I need a change in mindset, and I thought getting this off my chest here was a good first step since I don't have much people to talk to about this. Please ask questions and share thoughts so I get a better perspective on this. Thank you ^^