I think if she was Rowling would have told us but maybe she will say she was in her Encyclopedia.

really? i had no idea she was anywhere near his age. But since you say so, i'd say she'd have to be, unless she was like harry,ron, & hermione, always getting into trouble trying to know more than she should...which sounds like her. :)

Yes she's some years younger isn't she?

I think Slughorn would have liked to have her for the "collection" but she wouldn't have been so keen on it. I mean...he's a Slytherin!

I agree with Christina. Slughorn was all about name-dropping. I think he would have said something (especially when he and Harry had the talk about whether he was prejudiced or not) about the current Deputy Headmistress/Head of Gryffindor House being in the Club.

Actually, Minerva is OLDER than Voldemort. Since she started Hogwarts in 1937 and Tom Riddle in 1938, we can be certain that she was a year above the boy. As for being in the Slug Club, I kinda doubt it. We know that Tom was a member, but whether she was is unknown.

A year older is still "roughly around" his age...