Pottermore Speculation: Who? Whom? Which Witch?

So... this was today's "trick" and while Pottermore has been so far a bit underwhelming in it's event, this tid-bit has prompted more discussion than the previous announcement of new spells.  As such, it's time for speculation and analysis after the break!
Possible suspects:

• Mafalda Hopkirk: A quick reminder: she was head of Improper use of Magic's office it would make sense that she worked her way up, and given she was a stickler for the rules, it's possible, and it does have something to do with Order of the Phoenix, though it seems unlikely based on what we know from the new chapters. 
• Hermione Weasley: Probably a no as it's epilogue related, though you never know, either way, this is slightly less likely than Mafilda and it is more likely to be what seems to be the general consensus... 
• Dolores Umbridge: This one is most likely. While I've seen the argument that Dolores wouldn't take a "lowly" job, she seems to be able to move up rather quickly, and I would have thought that she was talented and rather skilled, as she was in Slytherin according to word of Rowling. In addition, she will be seen in a moment, and featured prominently, unlike Mafalda. So, what does this mean? We should see something interesting as Pottermore and Rowling finally shed a bit more light on our most unliked character.