Possible Clues:

• Social worker around university, running an agony column?
• "Charley's __": Brandon Thomas farce
• Volunteer baby sitter, sometimes
• Relation isn't in plural form when spoken
• Mame, relatively speaking
• In partnership with 33 across?
• After tea 28 down's sister would make fun of one
• Family title
• Relative value, not preserving the right of every couple
• Potential baby sitter