Is the questioner sinful because her loose clothing clings to her body due to the wind, and must she buy an abaya to avoid that?

There is no sin upon you for what is revealed of your body due to the wind, if you are wearing loose clothing that does not describe the color of the skin, based on Khalil's statement in his abridgment: "And it is disliked that which defines, but not by wind." And Al-Alusi said: "What appears of it without intention, such as if the wind exposed it, then they are not held accountable for it." As for tight clothing, which is forbidden, it describes the parts of the body and accentuates the allure. An example of this is what was reported from Usama (may Allah be pleased with him) regarding the Coptic garment that the Prophet (peace and blessings be upon him) gave to his wife, whereupon he commanded her to wear a ghilalah (undergarment) beneath it, fearing that it would describe the size of her bones.