As the number of times of breastfeeding is unknown, you should take precaution and not consider it such breastfeeding that prevents marriage, as there is a possibility that its conditions were not met. Thus, the mentioned women are not considered Mahrams for you. As there is also a possibility that its conditions were met, then you had better not marry one of them either. It is known in Shari`ah (Islamic law) that precaution in marriage is observed more carefully than anything else, according to the saying of the Prophet (peace be upon him),
Leave what causes you doubt and turn to what does not cause you doubt.
The Prophet (peace be upon him) also said,
Those who guard themselves against doubtful things keep their religion and honor blameless.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.