Parental Controls don't seem to work on my Flint 2 running 4.9.0

I recently installed a Flint 2 router in my home. I don’t want my young daughter accessing YouTube from her WIFI tablet and she is particularly good at getting the YouTube App reinstalled.

I thought I’d set up parental control and block her tablet from YouTube in Flow Control → Parental Control. It looked easy to set up, but seems to have done nothing and I can access YouTube from her tablet no problem.

Does anyone know what I am doing wrong please?

I assume that the YouTube app will not request the same resources as YouTube on the web. So it might fail to get blocked by the parental control.

However a better way would be to enforce restrictions on her tablet directly. Is it iOS or Android?

It’s an Android tablet, the problem for me enforcing with parental control is that the Tablet use to be her older sisters’ and so the account is her sisters. I’m OK with the older child accessing YouTube on her phone. I’ve not moved the Tablet over to the younger childs account primarily because they share a TocaBoca account which uses Google and we’ve spent money on things for them.