The Secret — Ruth Thomas

Mum knew she shouldn't have left the children alone. That was why she was hurrying home, running to catch the evening train. She was so worried about Nicky and Roy that she didn't hear the thief come up behind her; she didn't look carefully when she dashed across the road...

Back at home Nicky is finding it harder and harder to reassure her younger brother Roy. Soon the children are running out of money and the neighbours are getting suspicious. But whatever happens, Nicky is certain of one thing -- she will NEVER tell.