Maseches Niddah, Chapter 9, Mishnah 4. This mishnah lists a number of cases in which a woman may not eat Terumah or ma'aser. This is how it goes.
The cases in which a woman does not eat Terumah:
"Bas Yisrael hame'oreses l'kohen" - the daughter of a Yisrael who has been betrothed to a kohen, but has not yet married him and has not yet entered the chuppah. Although by Torah law she would be permitted to eat Terumah, the Sages decreed that she may not eat it as long as the marriage has not taken place.
"Me'ubberes b'kohen" - a woman who is pregnant by a kohen not through marriage, where there was nothing between them but a physical relationship. Once the child is born she will be able to eat Terumah on account of the child, but the mere fact that she is pregnant by a kohen is not enough.
"Shomeres yavam l'kohen" - a woman whose husband died and whose husband's brother is a kohen, and she is waiting for yibum. This connection is not sufficient to permit her to eat Terumah.
"V'chein bas kohen l'Yisrael":
These same three cases are stated in the opposite direction as well, regarding the daughter of a kohen who had been eating Terumah in her father's house:
Betrothal to a Yisrael - this alone is enough to remove from her the Terumah that she had been eating in her father's house.
Pregnant by a Yisrael - this too prevents her from eating Terumah in her father's house.
Shomeres yavam to a Yisrael - when her husband died, one might have thought that she would return as a widow to her father's house and eat Terumah, but her connection for yibum to a Yisrael prevents this.
Ma'aser rishon - according to Rabbi Meir:
The mishnah goes on to list these same cases with regard to a Levi as well. The Gemara explains that our mishnah follows the view of Rabbi Meir, who holds that ma'aser rishon - the first tenth, which is given to the Levi - has the same status as Terumah: just as Terumah may be eaten only by a kohen, so too ma'aser may be eaten only by a Levi. The halachah does not follow this opinion, but our mishnah follows this line of thinking.
Therefore: the daughter of a Yisrael who is betrothed to a Levi, or who is pregnant by a Levi, or who is a shomeres yavam to a Levi, and likewise the reverse - the daughter of a Levi who has one of these relationships with a Yisrael - "lo sochal b'ma'aser" - she may not eat ma'aser. In each one of these cases she is not permitted to eat ma'aser.
The daughter of a Levi with a kohen and the daughter of a kohen with a Levi:
The daughter of a Levi who is betrothed to a kohen, or pregnant by a kohen, or a shomeres yavam to a kohen, and likewise the daughter of a kohen with a Levi - "lo sochal lo b'Terumah v'lo b'ma'aser" - she eats neither Terumah nor ma'aser. Because of her situation, she does not belong fully either to the kohanim or to the Levi'im.
The Gemara explains that this final clause is not to be taken at face value; rather, it deals with a woman who wishes to receive a portion of Terumah at the threshing floors, in a place where the custom was to distribute it there. Our mishnah rules that she is not allowed to receive a portion of Terumah, neither the daughter of a kohen nor the daughter of a Levi. The reason is a decree, lest people come to give Terumah to the daughter of a Yisrael who was divorced from a kohen, or ma'aser to the daughter of a Yisrael who was divorced from a Levi, without noticing that they had been eating Terumah and ma'aser only by virtue of their husbands.
It is worth noting that this decree applies to a married woman as well, and not only to one who is merely betrothed. The reason the mishnah used the language of betrothal is that the previous section dealt with a woman betrothed to a kohen or to a Levi; in practice, however, the decree applies to any woman who married a kohen or a Levi. Again, the reason for the decree is the concern that after she is divorced people will not notice that she had been eating only by virtue of her husband, and that she is no longer permitted to eat, and they will come to give her Terumah in a forbidden manner.
In summary: this mishnah listed the situations in which a woman does not eat Terumah or ma'aser - a betrothed woman, a pregnant woman and a shomeres yavam - whether she is the daughter of a Yisrael connected to a kohen or a Levi, or the daughter of a kohen or of a Levi connected to a Yisrael, or the daughter of a Levi with a kohen and the daughter of a kohen with a Levi, who eat neither this nor that. We saw that the mishnah follows the view of Rabbi Meir regarding ma'aser rishon, and that the final clause deals with the distribution of Terumah at the threshing floor, which was forbidden because of a decree lest people come to give Terumah to a woman who is not fit to receive it.