She needs to find a way to get to sleep and not use stimulants to keep awake. She will end up sleeping even less and using more stimulants creating a negative cycle.

Is she doing long driving, like an interstate truck driver or sales rep? or is she just constantly sleepy?
if she is always sleepy she may have a mineral or vit inbalance. is it metabolism relative? maybe she could take a multi vitamin or some B vitamins they are used for energy issues.