This is a gem from the Betty Crocker Picture Cook Book. I don’t know about this one in the Easter egg shells – likely it’s not really safe.
Colorful Gelatin Easter Eggs
Save egg shells where only the top has been broken away (who does that?) when the egg was removed. Fill thoroughly dried shells with fruit-flavored gelatin in different colors. Set filled egg shells in muffin cups to chill until gelatin is firm. Break away shells. Serve in little nests of coconut on large chop plate.
Oh boy. I think Jello Jigglers are safer!