Answered by Shaykh Yusuf Weltch
Question Summary
Is a woman required to wear thick clothing in the prayer?
Question Answer
In the Name of Allah, the Most Merciful and Compassionate
A woman is required to cover all parts of her body in the prayer with such a garment that the tone of one’s skin cannot be seen through it. Even though one may be able to see light through it, it is still permissible to wear in the prayer; if it reaches the extent that the skin tone can be seen, that is too thin. [Ibn ‘Abidin, Radd al-Muhtar]
Hope this helps
Allah knows best
[Shaykh] Yusuf Weltch
Checked and Approved by Shaykh Faraz Rabbani