What is the ruling if a menstruating woman departs without performing the farewell circumambulation (Wada') and becomes pure before leaving the settlement boundaries?

Primary text

If a woman in menstruation departs without performing the farewell circumambulation (Wada') and achieves ritual purity before leaving the boundaries of the settlement ('al-Bunyan'), she must return, perform Ghusl (ritual bath), and then perform the farewell circumambulation. This is because she is still considered to be in the ruling of residency, evidenced by the fact that she cannot avail herself of concessions (Rukhas) related to travel. If returning is not possible, or if she departed without justification (without menstruation), she owes a compensatory sacrifice (Dam).