The expression put to sleep and put to bed are often misused by the non-native speakers. When you want to send your children to bed (to sleep), you say “I put them to bed.”
Put to sleep = to give lethal injection in order to kill someone as in death penalty or sick animals.
• We had to put our dog to sleep because it was very sick.
Send (someone) = to permit or enable to attend a term or session
• I sent my daughter to college.
So, don’t you ever say “I put my children to sleep” anymore, because people might think you’re a psycho! 😀