Kesuvos12: 3
אַלְמָנָה שֶׁאָמְרָה: ,,אִי אֶפְשִׁי לָזוּז מִבֵּית בַּעְלִי” — אֵין הַיּוֹרְשִׁין יְכוֹלִין לוֹמַר לָהּ: ,,לְכִי לְבֵית אָבִיךְ, וְאָנוּ זָנִין אוֹתָךְ”; אֶלָּא זָנִין אוֹתָהּ בְּבֵית בַּעְלָהּ,, וְנוֹתְנִין לָהּ מָדוֹר לְפִי כְבוֹדָהּ.  אָמְרָה: ,,אִי אֶפְשִׁי לָזוּז מִבֵּית אַבָּא” — יְכוֹלִים הַיּוֹרְשִׁים לוֹמַר לָהּ: ,,אִם אַתְּ אֶצְלֵנוּ — יֶשׁ לִיךְ מְזוֹנוֹת; וְאִם אֵין אַתְּ אֶצְלֵנוּ — אֵין לִיךְ מְזוֹנוֹת.” אִם הָיְתָה טוֹעֶנֶת מִפְּנֵי שֶׁהִיא יַלְדָּה וְהֵן יְלָדִים — זָנִין אוֹתָהּ וְהִיא בְּבֵית אָבִיהָ.
[If] a widow says: “I do not wish to move from my husband’s house,” the heirs cannot say to her: “Go to your father’s house, and we will support you”; rather, they must support her in her husband’s house, and they give her a residence according to her hon-or.  [If] she says: “I do not wish to move from my father’s house,” the heirs may say to her: “If you are with us, you will have sustenance; but if you are not with us, you will have no sustenance.” If she claims that [it is] because she is young and they are young, they must support her while she is in her father’s house.
Kesuvos12: 4
כָּל זְמַן שֶׁהִיא בְּבֵית אָבִיהָ — גּוֹבָה כְתֻבָּתָהּ לְעוֹלָם. כָּל זְמַן שֶׁהִיא בְּבֵית בַּעְלָהּ — גּוֹבָה כְתֻבָּתָהּ עַד עֶשְׂרִים וְחָמֵשׁ שָׁנִים, שֶׁיֵּשׁ בְּעֶשְׂרִים וְחָמֵשׁ שָׁנִים שֶׁתַּעֲשֶׂה טוֹבָה כְּנֶגֶד כְּתֻבָּתָהּ; דִּבְרֵי רַבִּי מֵאִיר, שֶׁאָמַר מִשּׁוּם רַבָּן שִׁמְעוֹן בֶּן גַּמְלִיאֵל. וַחֲכָמִים אוֹמְרִים: כָּל זְמַן שֶׁהִיא בְּבֵית בַּעְלָהּ — גּוֹבָה כְתֻבָּתָהּ לְעוֹלָם; כָּל זְמַן שֶׁהִיא בְּבֵית אָבִיהָ — גּוֹבָה כְתֻבָּתָהּ עַד עֶשְׂרִים וְחָמֵשׁ שָׁנִים. מֵתָה — יוֹרְשֶׁיהָ מַזְכִּירִין כְּתֻבָּתָהּ עַד עֶשְׂרִים וְחָמֵשׁ שָׁנִים.
As long as she is in her father’s house, she can collect her kesubah forever. As long as she is in her husband’s house, she can col-lect her kesubah until [the end of] twenty-five years, for in twenty-five years, she has [the opportunity] to do favors corre-sponding to [the amount of] her kesubah; [these are] the words of R’ Meir, which he stated in the name of Rabban Shimon ben Gamliel. The Sages, however, say: As long as she is in her husband’s house, she may collect her kesubah forever; as long as she is in her father’s house, she may collect her kesubah until [the end of] twenty-five years. If she dies, her heirs may claim her kesubah until [the end of] twenty-five years.