Child
Kid
The child radical and the child kanji are exactly the same.
し, す
こ
None
The main reading here is し, so to remember it we'll use this mnemonic:
There is a child standing in front of you. You look closely at the child but something seems wrong. You rub your eyes and when you open them again, there is a sheep (し) in front of you. A sheep?! You yelp, blink again, and it's back to being a child. Are… are all children really just sheep?