My question is about the 'awrah of a female slave, meaning a bondswoman?

Allah Almighty commanded the covering of 'awrah (private parts) and the wearing of adornment, especially at every mosque. He also denounced those who forbid Allah's adornment. Among the etiquettes of Islam is to cover what is deemed offensive to expose. For this reason, covering is stipulated for prayer. Scholars have defined the 'awrah of a man and a female slave (amah) as being between the navel and the knee, as mentioned in prophetic hadiths.