What is the 'awrah of a mother in front of her young and adult children?

The 'awrah (intimate parts) of a mother in front of her young children varies depending on their understanding and age. If they comprehend the meaning of exposure, then the mother should only appear before them with the extremities that adult mahrams (unmarriageable kin) are permitted to see. This is for the purpose of upbringing and training. However, if they do not understand the meaning of 'awrah, then there is no harm in the mother exposing some parts of her body in front of them, as they are not yet held accountable. Al-Qurtubi mentioned that this is the correct view, while some scholars hold the opinion that it is not permissible, and this is more cautious so that the child becomes accustomed to not seeing 'awrah.