"Is the child sleepy?"
Translation:¿El niño tiene sueño?
no, it means the child is tired. Estar cansado= To be tired. Tener sueño= To be sleepy.
Subtle, but I see what you are saying. It was tricky for me, because in English tired can also mean sleepy. But sleepy does not encompass all meanings of tired in English. So, you can be physically tired and that might make you want to sleep (to be sleepy), or you might just want to rest without sleeping (to just be tired).