Yes. It's called "folklore." In fact, did you know most Arthurian retellings use the names of characters from folklore too? *tongue in cheek* And, some nursey rhymes talk about dead people and the plaque. Shall we ban "Ring Round the Rosie"? Did folks get so excited about naming the space capsules after mythological figures?
Let's not get silly about this. Folklore is folklore and British folklore is different than American. That doesn't make it "real."
" One character is named Vablatsky (a play on the name of Madame Blavatsky, a theosophist of the 19th century). A class in "Transfiguration" (regardless of its sacrilegious context for us Muggles) also hints at familiarity with the "New Age" belief in stages of enlightenment, including that of "transfiguration". A closer reading might also reveal a woman author plagued by the perpetual adolescence of the rest of her generation and with very probable extracurricular interests in the occult. "