If a woman in post-natal bleeding becomes pure before forty days, may she fast, pray, and perform Hajj?

Q: Is it permissible for a woman with post-natal bleeding to fast, pray, and perform Hajj before forty days if she becomes pure?

A: Yes, it is permissible for her to fast, pray, and perform Hajj and 'Umrah, and it is permissible for her husband to have intercourse with her within the forty days if she becomes pure. So if she becomes pure after twenty days, she takes a bath, prays and fasts, and she is permissible for her husband.
And what is narrated from 'Uthman ibn Abi al-'As that he disliked it is understood as a recommendation of avoidance (makruh tanzi), and it is his independent legal reasoning, may Allah have mercy on him and be pleased with him, and there is no evidence for it.
And the correct view is that there is no harm in that if she becomes pure before forty days, for her purity is valid. If the blood returns to her within the forty days, the correct view is that she considers it post-natal bleeding for the duration of the forty days, but her past fasting during the state of purity, her prayer, and her Hajj are all valid; nothing of that is repeated as long as it occurred during the state of purity.