I wouldn't require someone to do an orbit on short final, "short" being inside 3nm from the threshold.
Especially the case when it's known the pilot is a beginner. The local aero club provides information to the tower to indicate if the pilot is a student.
One of the axioms of controlling is to always have an "out" - a good workable plan B. I find it highly desirable to also have a plan C, and maybe for real unusual situations, a D that can be cobbled together. If the spacing near the aerodrome is going to be tight, I would also communicate the plan B to the pilot/s affected in advance, so there are no nasty surprises.
3 mile final is probably not too close/low for most pilots to safely and happily handle an orbit (except low time students, maybe.) 2 miles probably is a bit close. 1 mile would be a no-no, unless the pilot was known to be experienced, and had indicated in advance acceptance of it.
Not enough info in post 1 to make any assumptions.