Read this excerpt from The Miracle Worker.

ANNIE: Oh, in grownups you have to, Mr. Anagnos. I mean in children it just seems a little – precocious, can I use that word?

ANAGNOS: Only if you can spell it.

ANNIE: Premature. So I hope at least she’s a bright one.

ANAGNOS: Deaf, blind, mute – who knows? She is like a little safe, locked, that no one can open. Perhaps there is a treasure inside.

ANNIE: Maybe it’s empty, too?

the servant does not kill the child oedipus as he was ordered to do because "he pitied the child" based on the oedipus rex story. the servant was ordered to kill the child because of the prophecy that predicted king laius' death. the king already had attempted to hurt oedipus by piercing oedipus's ankle. however, the servant did not finish the job and he rather saved the baby oedipus.

explanation:

because they were not just any seashells they were sally's seashells