I might add here that the Rambam makes a distinction between a case where most people in a city are pasul (but no one says anything) to a case where people are saying she (an unmarried woman) had sex with someone in particular or with others. In this last case, if people say she had sex with others besides the kohen we know about, then she cannot eat truma, but the fact that most people in the city are passul (invalid) would not harm her status of being abele to eat truma. That is to say this: Even when she says nothing, but we know she had sex with a kohen, and has given birth to a male child, she can eat truma. We do not care about the majority of people in the city unless people are claiming she had sex with others besides the kohen. But in the case of a betrothed woman, what she says matters. If she says nothing, the child is probably a bastard. But if she says she had sex with her betrothed husband, then she and the child are kosher. ,If the betrothed husband disagrees with her that is a case of one witness that is disagreed with by another, and the testimony of both is null and void and the child is definitely a bastard, but she is still considered kosher. See Laws of Truma 8, law 14, and Laws of Forbidden Relations chapter 15, laws 11 and 12-------------------------------I might add here that the רמב''ם makes a distinction between a case where most people in a city are פסול (but no one says anything) to a case where people are saying she (an unmarried woman) had sex with someone in particular or with others. In this last case, if people say she had sex with others besides the כהן we know about, then she cannot eat תרומה, but the fact that most people in the city are invalid would not harm her status of being able to eatתרומה . That is to say this: Even when she says nothing but we know she had sex with a כהן and has given birth to a male child, she can eat תרומה. we do not care about the majority of people in the city unless people are claiming she had sex with others besides the כהן. But in the case of a betrothed woman, what she says matters. if she says nothing the child is probably a bastard. But if she says she had sex with her betrothed husband she and the child are כשר. If the betrothed husband disagrees with her that is a case of one witness that is disagreed with by another and the testimony of both is null and void and the child is definitely a bastard, but she is still considered כשר. see הלכות of תרומה 8 הלכה 14 and הלכות of איסורי ביאה chapter 15 הלכות 11 and 12. The I think, but I am not sure, that some commentators consider people speaking to be the same category of people most people in the city are invalid. And I think רב שך considers people speaking to be identical with the phrase in the גמרא ofדיימא דעלמא ----------------In two places the Rambam deals with the question of an unmarried woman who had sex with someone. One place is in laws of truma. There the Rambam says nothing about if she says anything. Rather the case is we the court knows she had sex with a kohen. The other case is in laws on forbidden relations chapter 12, and there she is found pregnant and she says the father is kosher i.e., fit to marry a Jewess. There the Rambam does mention that most of the city is not valid. Still, she is believed. The above essay is based on the idea that we believe her in both cases unless people say otherwise. The fact of the majority of the city I think does not matter in either case.In two places the רמב''ם deals with the question of an פנויה who had sex with someone. One place is in laws of תרומה. There the רמב''ם says nothing about if she says anything. Rather the case is we the court knows she had sex with a כהן. The other case is in הלכות on איסורי ביאה chapter 12, and there she is found pregnant and she says the father is כשר i.e., fit to marry a Jewess. There the רמב''ם does mention that most of the city is not valid. Still, she is believed. The above essay is based on the idea that we believe her in both cases unless people say otherwise. The fact of the majority of the city פסוליםI think does not matter in either case.