J'ai Lu The secret of housemaid by Freida Mcfadden

With this new job, Millie seems to have landed on her feet. At the Garricks', a wealthy couple who own a sumptuous apartment overlooking Manhattan,she cleans and prepares meals in the magnificent kitchen. But she soon notices some shady dealings... Her boss, Douglas , is becoming increasingly moody. And why does his wife, Wendy, always stay locked in the guest room?