Ref. No. 1196/42-485
In the name of Allah the most Gracious the most Merciful
The answer to your question is as follows:
An eight-year-old girl is not obliged to cover her limbs. Those who see her without lust are not sinners. If one looks at such a girl with lust, he will be sinner. Thus, it is permissible to send her to school or maktab to learn the Qur'an with men. However, in the case of girls, precautionary measures should be taken as much as possible.
And Allah knows best
Darul Ifta
Darul Uloom Waqf Deoband