Possible Clues:

• Board groove
• Skirting round mate of Mother Superior?
• Panelled lower part of a wall
• What will father perform on the wall?
• Wood border running round room walls
• Part below a cornice
• Strange to keep a rejected part of wall
• Appeal to parent to replace part of wall specially decorated
• Implement with plug inserted in lower part of wall
• Decorated lower part of an interior wall