Hi, Musique -
Many chanteys can be made child-safe by excluding the risque verses. You won't be stuck with the same ones you're getting sick of. Do you have Stan Hugill's "Shanties from the Seven Seas" or Mystic Seaport's "Songs of the Sailors?" Also, former Hyde Street Pier chantey sing ranger Revell Carr and former school teacher Margaret Batt produced a book of traditional chanteys specifically for schools. let me know if interested.

Chanteyranger