אבן העזר ק״סEven HaEzer 160

Se’if 1א׳

יְבָמָה, שְׁלשָׁה חֳדָשִׁים (הָרִאשׁוֹנִים), נִזּוֹנֶת מִשֶּׁל בַּעְלָהּ וּמַעֲשֵׂה יָדֶיהָ לַיָּבָם; מִכָּאן וְאֵילָךְ אֵינָהּ נִזּוֹנֶת לֹא מִשֶּׁל בַּעַל וְלֹא מִשֶּׁל יָבָם. עָמַד בְּדִין לְאַחַר שְׁלשָׁה חֳדָשִׁים (רִיבָ"שׁ סִימָן ק"ד) וּתְבַעְתּוֹ לְיַבֵּם אוֹ לַחֲלֹץ לִפְנֵי בֵּית דִּין, וְנִתְרַצָּה לְיַבֵּם וְאֵרְעוֹ אֹנֶס, שֶׁחָלָה אוֹ שֶׁהֻצְרַךְ לִבְרֹחַ מֵחֲמַת מָמוֹן אוֹ מֵחֲמַת מְרָדִין, חַיָּב בִּמְזוֹנוֹתֶיהָ בְּלֹא שְׁבוּעָה:

The yevamah--for the first three months she is provided for from the estate of her [dead] husband, and her handiwork belongs to the yavam. After this point she is not provided for, neither by her husband nor by the yavam. If she goes to court after three months (Ribash, siman 104) and demands that he have levirate marriage with her or release her in front of the court, and he wants to have levirate marriage but an unforeseen circumstance prevents it, that he gets sick or must run away due to a financial matter or due to oppressors, he must supply her with sustenance without [her being obligated] for an oath.

Se’if 2ב׳

הִנִּיחָהּ מְעֻבֶּרֶת, הֲרֵי זוֹ נִזּוֹנֶת עַד שֶׁתֵּלֵד. יָלְדָה וָלָד שֶׁל קְיָמָא, הֲרֵי זוֹ נִזּוֹנֶת כָּל יְמֵי אַלְמְנוּתָהּ, כִּשְׁאָר כָּל הַנָּשִׁים:

If he left her pregnant, she is provided for until she gives birth. If she gives birth to a viable fetus, she is provided for as long as she is a widow, as are all women.

Se’if 3ג׳

נָפְלָה לִפְנֵי יָבָם קָטָן, אֵין לָהּ מְזוֹנוֹת עַד שֶׁיִּגְדַּל. הַגָּה: יָלְדָה סְפֵק נֵפֶל, שֶׁדִּינָהּ לַחֲלֹץ וְלֹא לְהִתְיַבֵּם, כְּמוֹ שֶׁנִּתְבָּאֵר לְעֵיל סִימָן קנ"ו, נוֹטֶלֶת כְּתֻבָּתָהּ מִיָּד (הג"מ). יֵשׁ אוֹמְרִים הָא דְּאֵינָהּ נִזּוֹנֶת מִשֶּׁל יָבָם קָטָן, הַיְנוּ מִנְּכָסָיו, וַאֲפִלּוּ נְדוּנְיָא שֶׁהִכְנִיסָה לְבַעְלָהּ וְהֶחֱזִיק בָּהּ; אֲבָל לֹא הֶחֱזִיק בַּנְּדוּנְיָא שֶׁלָּהּ, כְּגוֹן שֶׁעֲדַיִן מֻנַּחַת בְּיַד שָׁלִישׁ, נִזּוֹנֶת מִנְּדוּנְיָתָהּ, כָּל שֶׁכֵּן בְּמָקוֹם שֶׁהִיא אוֹמֶרֶת שֶׁיִּתְּנוּ הַנְּכָסִים לְיָדָהּ וְהִיא רוֹצָה לְקַיֵּם הַקֶּרֶן עַד שֶׁיִּגְדַּל הַנַּעַר וְלִזּוֹן מִן הָרֶוַח, שֶׁנּוֹתְנִין הַמָּעוֹת לְיָדָהּ (שָׁם בְּשֵׁם הָרִי"ף):

If she fell before a yavam who is a minor she does not receive sustenance from him until he becomes and adult. Rema: If she gave birth to a suspected stillborn, when she would be required to perform Chalitzah and not Yibum, as was explained earlier in Se'if 156 she takes her Ketubah money right away. There are those who say that she only doesn't receive sustenance from a minor yavam's property, even the dowry that she brought in for her original husband and he [the minor] seized, however if he did not take possession of her dowry, as in a case where a third party is holding it, she receives sustenance from her dowry, certainly in a case where she says that the property should be given to her possession and she would like to maintain the principal until the minor becomes an adult and she will get sustenance from the profits that they give her the money.