Was the Khath'amite woman mentioned in Ibn Abbas's Hadith a محرم (unmarriageable kin) or not?

The summary of the answer is that Ibn Hajar is of the opinion that the story of the Khath'amiyyah woman occurred after the throwing of the Jamrat al-'Aqabah. Sheikh Al-Albani adopted this view and assumed that she had exited her state of ihram based on the premise that a person in ihram exits it after throwing the Jamrah.

However, it was pointed out that Al-Albani did not definitively state this, and that Ash-Shafi'i and Ahmad do not consider one to exit ihram until two of three rites have been performed (such as throwing the Jamrah with shaving or sacrificing). Therefore, it cannot be definitively stated that the Khath'amiyyah woman had exited her state of ihram, and the default remains that she was in a state of ihram until proven otherwise.