Possible Clues:

• Where girls learn social graces, and hint to what the first words of 18- and 62-Across and 3- and 30-Down have in common
• Where a young woman once learned social skills, and what each starred answer has
• A charming place, or what both halves of 17, 24, 50, and 61 Across are capable of doing
• Girls' educational establishment breaking up?
• Searching around in swimming group that trains young ladies
• Where social graces are taught ... and, with 'of,' a hint to the ends of 17-, 28-, and 44-Across
• Posh girls' establishment disposing of tutor?
• Perfect gin drunk on train -- source of refinement?
• Training academy swimmers on the last length?
• Teaching establishment getting rid of coach