- Since we already know that both of her sisters are animagi it seems like a fair bet that she is as well, but she hasn't shown any particular Animal Motif so far aside from the Falcon hood ornament on her car.
- Dean Grimm and Shirtliffe are inordinately close to each other, with Shirtliffe being the functional equivalent of a deputy head. In Thorn's Circle, Shirtliffe hints at her and Grimm frequently discussing Alex in private. Moreover, Shirtliffe one mentions she doesn't always agree with Dean Grimm, but she follows her anyway. We know that Charmbridge's conservative secretary, Mrs. Marmsley, disapproves of Shirtliffe for some reason. Grimm is the more feminine one, and Shirtliffe is masculine, with Alex comparing her to a biker.
- Lots and lots of clues here.
- That is, there are strong signals that Anna has a serious crush on Alexandra, and we don't really know what Alex's attractions are, strictly speaking. Remember, she only really dated Torvald because he was interested in her in the first place.
- Since in Greek mythology Medea was a servant of the goddess Hecate, and Inverarity's used naming to indicate relationships and provide clues to plot points before, it's entirely possible.
- Hecate might have had secret information that Abraham had to remove from her.
The hint couldn't be more obvious if it had a giant flashing arrow pointing at it.
The likely sequence of events: Alex, in the future, is going to stumble across the time turner hidden somewhere. So she's going to do some time travelling, eventually go back to that moment, Stun herself, and take that time turner, and put the one she found in the future on her past self, and put the one she got from her past self where she is going to find it in the future. (And either before or after that do some plot-relevant time travelling.)
If this is true, she has possibly been running around half of book three and all of book four, and it's possible she went back even farther than that. ('Possibly' because, although she does have to take the Slow Path according to the supposed rules of time travel, there are certainly magical ways to skip the passage of time...Petrification already does it in canon, if she figure out a way to do that and to have someone get her out of it.)
So the question is: Is there any (other) point in the timeline where she has already meddled?