And, perhaps second most importantly, she knew how to spot the members of Lord Voldemort's forces when they attempted to mingle with the Muggles. It was clear he chose his "ambassadors" to the Muggle world very carefully from amongst his Death Eaters. Likely they were all at least Half-bloods. Blood purity might have been a topic revered by many still living within the society she ran from, but the so-called Dark Lord was too pragmatic to dispose of anyone with magical blood as long as they served some use. Even Muggle-borns had been somewhat recruited. Not necessarily into his service as a Death Eater. More as secondary servants. Still useful for performing the drudgery that those with more pristine ancestry abhorred.