That got the point across to me.
“My English teacher, sister Agony, would rap my knuckles if I said “ofTen”.”
But she probably had no problem with other early modern holdovers like “vale” for “valley” in the Hail, Holy Queen - ahem!, in the Salve Regina - prayer.
You should have told her that “ofTen” was the Catholic pronunciation since the “T” was pronounced right up to the 17th century in English.