Baileys Irish Cream made a valiant attempt at keeping my wife asleep for the night after a stressful days work. By 9 pm I was on Splinter Cell with her comatose till half eleven. She went to bed, shortly followed by myself. 
My wife was awake at 1:30am and sat downstairs. It was around 4:30 that she stomped angrily into the bedroom and knocked a glass of water over. If we had owned a cat, I think it wouldn't been kicked at this point. Her anger radiated from her and I felt guilty for seeming to be asleep so I was awake then. I got up and went downstairs to lay on the couch in solidarity. My wife came from fighting with the bedclothes and we talked about her work/insomnia problems over a cup of tea for an hour. She's permanently wired anyway without work being too much to take. 
We probably grabbed an hours power sleep until 6;30.
Let's see if taking kalms on a night can help, failing that I'll slip her a horse tranquilliser.