What is the ruling on the prayer of a woman who is immodestly dressed, or one who covers her head but her clothes are tight?

If a woman covers what must be covered in prayer, then her prayer is valid. And if she is immodestly adorned outside of prayer, she is committing a grave sin and must repent. However, if she exposes any part of her 'awrah, such as her hair, during her prayer, her prayer is invalid. Praying in tight clothing that describes the size of the body is strongly disliked (makrooh karahah shadeedah).