Amazon Fire setup for kids not working

[WutheringFrights]

As I understand it you can set the Fire to ensure the DC do a set amount of minutes of games/books before they can watch any vids.
I'm sure I have set it up correctly but it is allowing them to go straight to video? Have I missed something really obvious?

You can definitely do this on the parental control setting, but I’m not sure if you can choose which order they do them in iyswim. So, you could say 30 mins video and 30 mins books but it only restricts it to just the books once the video tine has run out.

I'm sure I set up so that they have to acheive 'educational goals' first but it's letting them do whatever they want.
They've actually been really good and followed my instruction to do some educational games first but I don't want to be hovering over them every time they use it!