>- she's been sleeping too little and too light for a long time now,
When we are young, our bodies produce a natural sleep hormone which decreases as we age. Melatonin will restore restful sleep. Your mom probably needs 3 mg or more. Some people with serious illnesses such as cancer take 12 to 20 mg a night. Most people over the age of 40 probably need melatonin.
The one that I use is Natural Sleep Melatonin from the Life Extension Foundation ( http://www.lef.org
). Be wary of cheaper forms.