Sotah, Chapter Four, Mishnah Two
This mishnah lists women who became sotahs but do not drink the water. Some of them receive their ketubah and some dont. It all depends on why they dont drink. Some of these cases have already been mentioned in above mishnayoth.
1) And these are the [women] who do not drink and do not receive their ketubah:
a) She who says I am defiled;
b) When witnesses came [and testified] that she was defiled;
c) And she who says I refuse to drink.
2) When her husband says I am not letting her drink,
a) And when her husband has sexual relations with her on the journey [to Jerusalem] she receives her ketubah but does not drink.
3) If the husbands died before [the women] drank:
a) Beth Shammai says: they receive their ketubah but do not drink,
b) And Beth Hillel says: they do not drink and they do not receive their ketubah.
Section one: These women do not receive their ketubah because either they refused to drink or it became obvious that they had committed adultery. A woman who has committed adultery always forfeits her right to collect her ketubah.
Section two: If her husband is the reason that she doesnt drink, she does receive her ketubah. This can happen either because he stated outright that he doesnt want her to drink or because he had relations with her after she became a sotah (see above chapter one, mishnah three).
Section three: In this case, the husband warned his wife not to be secluded with a certain man and then she was. Before she had a chance to drink, the husband died. Everyone agrees that she does not drink the water. They disagree with regard to the ketubah. Beth Shammai holds that she collects the ketubah. The Talmud explains that Beth Shammai views a debt document (which a ketubah is) as if it has already been collected. Therefore the money stated in the ketubah is already hers, and unless the husbands heirs can prove otherwise, she gets to collect. Since they cant prove that she committed adultery, the ketubah belongs to her.
Beth Hillel holds that she loses her ketubah. They do not view debt documents as if the money has already been collected, and therefore the money is still part of her husbands estate. Hence, she must prove that she is owed the money and that she didnt commit adultery. Since she cannot drink the waters to prove her innocence, she loses her ketubah.