Horcruxes

As transcribed by various sources, JK Rowling describes Voldemort's horcrux creation schedule as follows:

Horcrux -- Murder victim

Tom Riddle's diary-- Moaning Myrtle
Marvolo Gaunt's Ring/Resurrection Stone -- Tom Riddle Senior
Helga Hufflepuff's Cup -- Hepzibah Smith
Salazar Slytherin's Locket -- A Muggle tramp
Rowena Ravenclaw's Diadem -- An Albanian peasant
Harry Potter -- N/A
Nagini -- Bertha Jorkins

But it doesn't make sense.

Moaning Myrtle was killed by the balilisk, and she's not mentioned at all in Dumbledore's explanations to Harry about the horcruxes, either. Furthermore, Dumbledore noted that Voldemort reserved horcrux making for significant murders, which means that the peasant and tramp also seem unlikely. And, finally, Dumbledore seems to think that Tom Riddle made Nagini into a horcrux when he killed the Riddle's old gardener, Frank Bryce, which may have qualified as a 'significant' murder.

Dumbledore also comments that Tom Riddle stopped wearing the Resurrection Stone/Peverell coat of arms ring once he turned it into a horcrux, and he's wearing the ring afterward in Slughorn's office, which seems inconsistent. It also seems somewhat inconsistent that Riddle already made two horcruxes before talking to Slughorn about the possibilities of making more than one horcrux. Tom Riddle may have been evil, but he wasn't totally stupid.

One possibility is that Tom created his first horcrux (the diary) when, at age 16, he killed his father and grandparents. This would tally with the age of the fragment of soul when Harry and Ginny encounter it in Chamber of Secrets.

Harry notices that the locket reflected Tom Riddle's handsome eyes, which seems to indicate that that horcrux predates the visit to Dumbledore when Voldemort had finally managed to efface his muggle father's features (gross). Voldemort also hides this horcrux in a location associated with his pre-Hogwart's childhood. So, perhaps poor Hepzibah Smith.

I rather like the idea that Regulus Black witnessed Voldemort making a horcrux following the death of one of the Order of the Phoenix and thought the locket was the only available horcrux.

So, do I think that JK Rowling is wrong? Or the transcribers? No, not really.

I think that Harry Potter inhabits a written universe and that one of the keys to good writing is revision. So, perhaps the horcrux schedule was revised.

and then I wonder whether or not there is actually something better to worry about...like why my last chunk of brie tastes like the plastic it was wrapped in...