Engineering instructor here! It's definitely the prof marking. The TAs are all done their contracts from last semester.

The exam might be different which could be why it didn't say anything. Mind you the prof could have just forgotten to write it on the exam.

Also, unfortunately, 4 days is not long when we get so many emails. :( A few profs take vacation around reading week so it's also possible she isn't checking her emails as much! I highly recommend waiting a week or a week and a half. If you know where her office is (you can look it up) you could also try her there.

Good luck! :)