Spring Spheres; or, Do We Live in a Christian Country?

A student volunteering in a Seattle public school classroom claims that she was told to call the plastic Easter eggs she wanted to distribute to the 3rd graders "spring spheres" instead of Easter eggs. Fox is now calling this the "War on Easter." 

Does distributing Easter eggs in public schools constitute the endorsement of a specific religion? Should public institutions (government, public schools etc) be allowed to celebrate religious holidays or not? Does Hawken - a private institution, but a secular one - do a good job in this regard?

Toronto Star article