Sounds like an opt-in filter should satisfy your desires perfectly!
Do you have numbers? I was very much surprised reading about family support/progressing in ones job aged 35+ etc. on this very board. Unless old readers drop out/don't return I'd guess that the number of parents here should statistically increase - and I don't think the number's insignificant. Start a poll?
This parent here considers the idea of filtering content utterly wrong, but what really upsets me are your statements along these lines here:
"Whiilst I may be a responsible parent and will turn on filters; many will not."
K, not my native language and all. I'm certainly misparsing the sentence and you don't actually claim that being a reasonable parent and turning the filters on is connected, people NOT turning that thing on aren't reasonable parents? Because that's what I get out of that statement..