This woman ruled france until her son charles was old enough to rule.

The woman that ruled France until her son Charles was old enough to rule wa Catherine de Medici.

Explanation:

Henry II, husband of Catherine and father of Charles IX, died in 1559. Charles, his first-born, was only 8 years old, so during the ten years that had to wait to ascend the throne, the regency was entrusted to his mother Catherine de Medicis, who governed until the coming of age of the king.