Praise be to Allah.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said:
It is not permissible for her to do ghusl and perform tawaaf until she is certain that she is pure (i.e., that her nifaas has ended).
From the words “started to” in the question it may be understood that she has not become completely pure; she has to be completely pure. When she becomes pure (i.e., the nifaas ends), she should do ghusl and do tawaaf and saa’i. If she does saa’i before tawaaf that does not matter, because the Prophet (peace and blessings of Allaah be upon him) was asked about the Hajj of one who had done saa’i before tawaaf, and he said, “That does not matter.”