Possible Clues:

• Society-page fodder
• Given some tea she would make this occasion quite lively
• Benefit event, often
• To have tea at the end of the celebration would have made one quite lively
• A convict turns up for a festive occasion
• Delay held up a celebration
• festivity
• Special festivity
• Benefit, often
• 17 across would be enough to make this lively occasion come to life