There is no obligation upon the menstruating woman or the woman with postpartum bleeding to perform the farewell Tawaf, according to the authentic narration from Ibn 'Abbas, may Allah be pleased with him, who said:
"The people were ordered (i.e. by the Prophet salallaahu alaihi wasallam) to make their last commission (the circumambulation of) the house (of Allah), except that this has been removed as an obligation upon the menstruating woman." [al-Bukhari no.1755 and Muslim no.1328.]
And the ruling for the woman with postpartum bleeding is the same, according to the scholars.