Seven-year-old boys and girls should be asked to offer Salah so that they get used to it, and it is considered Nafilah (supererogatory). A young girl should offer Salah in suitable clothes for her, but not revealing clothes; she should wear loose clothes, so that she gets used to them, and as she might cause Fitnah (temptation). As for Hijab, it is not necessary for her, according to the saying of the Prophet (peace be upon him):
Allah does not accept the Salah of a woman who menstruates unless she wears the Hijab.
A woman who menstruates here refers to an adult woman.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.