Fire 7 Kids

My inlaws gifted my toddler a Fire 7 Kids tablet over a year ago and it's been sitting in the box unused in my basement since (don't buy someone else's toddler a tablet without parents permission...anyway). We have a very long car trip coming up so, I figured I would finally pull it out. I was hopin

I love my children, but they're too smart for their own good.

Under each of their child profiles, I have Web Settings -> Enable Web Browser disabled.
I also have Child Settings -> Daily Goals & Time Limits, set up so that they should only have 1 hour of screen time per day.

I caught my oldest

10GB internal storage with 7.34GB (at time of posting) taken up by "Miscellaneous/Others". I really don't want to have to download any kind of cleaner app onto either computer or it itself but I can't find any other way to clear this out.

Also, why in the names of the gods can you find nothing when

I just got my Niece and Nephew fire 7 Kids (12th)
I put a 256gb Micro SDXC card in each one and was loading them up with mp4 movies that will play in my adult profile from the added memory card but I can't find a way to get to the memory card from the Kids profiles?
Is there a particular folder

https://www.amazon.com/Fire-7-Kids-Edition-Tablet/dp/B07H8WS1FT

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That's the tablet that my stepdaughter has. I have a Windows 10 PC and am having a helluva time adding content to the tablet. I've got some ebook files and pictures that I'd like to throw on there. When I connect it to the