You'd have to show her how to login to the web GUI and temporarily disable it I think, but I wonder if it's the use case.
If you're enabling ad filtering on the DNS level on your router, its more along the lines of forced ad filtering on your entire network, so you're kind of sacrificing user configurability for global ad filtering on your network.
Personally, I've only had the experience of a broken webpage once in two and a half years of using it.
I think it is basically that a website would want to work if an external service failed. DNS blocking looks like that, whereas editing the page content is obviously detectable.
If you're enabling ad filtering on the DNS level on your router, its more along the lines of forced ad filtering on your entire network, so you're kind of sacrificing user configurability for global ad filtering on your network.
Personally, I've only had the experience of a broken webpage once in two and a half years of using it.