Does their status as pure-bloods apply to every single family member or just most them? There could have been family members who married non-pure-bloods and had half-blood children and etc.
It basically applied to every single family member Cantankerus Nott believed was part of one of the 28 families, and all others were disavowed. That's how pure-blood supremacy works. You just take what you want and need, and deny what doesn't fit your narrative.
