Is it permissible to take one's mother to the market while her abaya is tight-fitting?

First: Advise your mother gently not to wear an abaya that defines her body, and to adhere to the conditions of the Sharia-compliant hijab by ensuring it is wide and loose.

Second: If your mother is going to the market anyway, then you should accompany her to protect her and minimize any wrongdoing as much as possible.