They're doing it again. She notices it, from the corner of her eye, as she is grading papers and sipping from a cup of tea while the class is practicing size-related transfiguration (changing rats into their house mascots, but very small versions).
She wonders if she ought to catch them at it sometime, perhaps make some snide comment concerning how hard it must be to do one's work with only one hand.
But one thing that life has taught Minerva is that addressing some things directly is as dangerous as the things themselves.
Granger is awkward, doesn't know what to do, whether she ought to say something. She is jealous, probably, as well; jealous that her friends have found a closeness to each other (albeit an awkward, nervous, teenaged Gryffindor one), and almost certainly fears that she will be shut out even further. She was the later addition to their triumvirate, and there are so many more differences between herself and the boys that she has undoubtedly always felt that her spot was much more tenuous. The arguments the three of them had in their third year prove that.
But she knows that they will work past that, and that if they do not, then it is for the best. Minerva has found that, as much distaste as she has for the idea of fate, it is sometimes the only thing that she *can* believe in, and if the friendship of those children is fated to endure, then it will.
But what happens, children, when you get caught? she asks them silently. Oh, certainly as long as your time together does not interfere with or hinder your studies, it will not be punished. Expulsion, detentions -- of course not, not so long as you keep in mind that there is a time and a place for everything. The reactions of your fellow students are harder to predict, but Hogwarts has always tried to be a welcoming place, and more often than not, it has succeeded.
Nobody deserves to die for loving, but nobody deserves to be used as a way to hurt those they love, either.
But she wouldn't expect them to understand that. Not yet.
They are in the midst of a war, though, and there is little that will stop them from understanding it one day.
"No, Thomas," McGonagall says as Dean asks her something. "You do not get points for having Transfigured your rat into an invisible lion. I know it's under the table, and if I haven't seen a lion on your desk by the end of class, you'll be... "
She sees, out of the corner of her eye, that Harry and Ron have cast guilty, nervous glances at each other and at her when she mentions that she knows what's under the table. She does not look at them.