treasured child; beloved child
An affectionate expression for a child who is cherished like a treasure. Often used by parents or family members.
彼女は両親にとって宝の子だ。
She is a treasured child to her parents.
初めての孫はまさに宝の子だった。
The first grandchild was truly a treasured child.
Composed of 宝 (treasure) + の (possessive particle) + 子 (child). The exact origin is uncertain, but it is a natural metaphorical expression.