Family Christmas Cryptic

1234567891011121314151617181920
Across
  1. 4. Worry head off about this kid
  2. 6. He conserves energy input
  3. 9. This kid sung a medley
  4. 10. Family with German, revolutionary and two students
  5. 11. This kid’s a helper, up to a point
  6. 12. Family cat has short tail, right?
  7. 17. Woman in Nice earthquake
  8. 18. Hidden titan natural
  9. 19. Tortured soul, that’s her
  10. 20. She’s mostly great with directions
Down
  1. 1. Sounds like he’d steal from an insect
  2. 2. First of duo, with impatient follower
  3. 3. Kid playing game in the middle of lunch
  4. 5. Bloke inspiring loud laughter at first
  5. 7. Someone’s the centre of attention in banjo show
  6. 8. Woman with claret – hot mess
  7. 11. Man takes beer (unknown quantity) and referees centrally
  8. 12. Object to one who would turn back time for family
  9. 13. One hops around a woman
  10. 14. Bravo spaceman!
  11. 15. She’s a laugh, and reportedly too wise around the French
  12. 16. She starts breakdancing with her underwear on backwards