All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Shaykh Ibn ‘Uthaymeen said: "If a woman who had post-partum bleeding attained purity before the completion of the forty days, she should perform Ghusl, then she can do all the acts of worship that pure women can do, even performing Tawaaf. This is because there is no specified minimum period of time for post-partum bleeding. If she did not attain purity, her Hajj will be valid, but she should not perform Tawaaf until she attains purity. This is because the Prophet, sallallaahu ‘alayhi wa sallam, prevented women who were menstruating from performing Tawaaf and a woman who has post-partum bleeding takes the same ruling."
Allaah Knows best.