What they were making was a bag for the Psammead.

Each worked at a half of the bag.
jane's half had four-leaved shamrocks embroidered on it.

They were the only things she could do (because she had been taught how at school, and, fortunately, some of the silk she had been taught with was left over).

And even so, Anthea had to draw the pattern for her.

Anthea's side of the bag had letters on it--worked hastily but affectionately in chain stitch.