Is it permissible for a woman to wear a tight blouse (body) under her khimar without a sleeved abaya, such that the blouse delineates her arm or body when she raises her hand or when the wind blows, or delineates her arm if it is under the idna' without a long-sleeved abaya over it?

The Islamic Law commanded modesty (ستر) without specifying a particular garment. Therefore, if modesty is achieved by wearing the khimar over a "body" garment, there is no harm in that. It is recommended for believing women to strive for modesty in its most complete forms. However, if it is highly probable that the khimar will become uncovered, revealing what is underneath it in a way that describes the body's size, then the ruling on such clothing has been previously clarified.