Originally, the first letter of each of the Cuckoo's names was supposed to spell out the word "spice" when put in proper sequence, Sophie, Phoebe, Irma, Celeste and Esme, a reference to the British pop group, the Spice Girls.
They were first called the Stepford Cuckoos in New X-Men, vol. 1 #123 (April 2002), which was also the first issue in which Esme was named.