Only when written 御子 / み子
Christian term; refers specifically to Jesus as the Son of God. Often used in hymns, prayers, and biblical contexts.
We pray 'Son of God, Jesus Christ' at church.
Christmas is the day we celebrate the birth of the Son of God.
The prince will enter university next year.
The princess's engagement was announced.
王子 is a general term for 'prince', not limited to imperial family members. 御子/皇子/皇女 specifically refers to children of the emperor.
王女 is a general term for 'princess', not limited to imperial family members. 皇女 is specifically a daughter of the emperor.
Standard kanji spelling for both the Christian 'Son of God' and the imperial child sense.
Specifically a male imperial child; the kanji 皇 means 'emperor' and 子 means 'child'.
Specifically a female imperial child; the kanji 皇 means 'emperor' and 女 means 'woman/daughter'.
Mixed kana-kanji spelling sometimes used in Christian contexts to emphasize the honorific prefix み.
The reading みこ is a combination of the honorific prefix 御 (み) and 子 (こ, 'child'). The kanji spellings vary by context: 御子 for the Christian Son of God, 皇子 for an imperial prince, and 皇女 for an imperial princess.