You must be from USA. In Europe you give tea even to toddlers and they sleep just fine. You mistook tea for coffee lol (Americans...)
Coffee usually has about twice as much caffeine per cup as tea, but that depends a lot on the variety of tea and the brewing method/amount used.
Europeans have a tendency to not make the distinction between herbal infusion and tea... No one is giving tea to toddlers, well I hope not.