Mary has some sense of the requirements of subtlety.

If she were in Milliways, for example, she would respond to this, quite reasonably, that Mr. Wolfe does not care in the least if any of the young ladies are attractive. But she is not in Milliways, and so she snaps her mouth shut and glowers at Galadan instead - calling her a good student does not make up for creating imaginary missing work for her; he could surely have thought of a better excuse!

The discussion of this matter had better take a while.