There's an answer.

He told me not to tell nobody who sent it, and not to give it to nobody on earth but you, and how to slip in through the hedge and try and find you in the garden when nobody was lookin', and he give a pencil for you to answer on the back of it, and a dollar." Miss Betty took the note, glancing once over her shoulder at the house, but Mrs.Tanberry was still occupied with the Maiden, and no one was in sight.

She read the message hastily.
"I have obeyed you, and shall always.

You have not sent for me.

Perhaps that was because there was no time when you thought it safe.