Related for Ketubot 9:6
הָלְכָה מִקֶּבֶר בַּעְלָהּ לְבֵית אָבִיהָ אוֹ שֶׁחָזְרָה לְבֵית חָמִיהָ, וְלֹא נַעֲשֵׂית אַפּוֹטְרוֹפָּא, אֵין הַיּוֹרְשִׁין מַשְׁבִּיעִין אוֹתָהּ. וְאִם נַעֲשֵׂית אַפּוֹטְרוֹפָּא, הַיּוֹרְשִׁין מַשְׁבִּיעִין אוֹתָהּ עַל הֶעָתִיד לָבֹא וְאֵין מַשְׁבִּיעִין אוֹתָהּ עַל מַה שֶּׁעָבָר:
If she [the one her husband exempted from an oath] went from her husband's grave to her father's house [not occupying herself with the property anymore] or returned to the house of her in-laws and did not become a caretaker, the heirs cannot cause her to swear [in connection with her dealings between the death and the burial. For if the heirs could cause her to swear in this regard, because she would thereby be constrained to bring witnesses as to what she sold and bought for the burial of the dead, the body would remain unburied and would become repulsive.] And if she did become a caretaker, the heirs may cause her to swear as to the future [i.e., that she did not misappropriate anything in her caretaker dealings after her husband's death. For his having exempted her does not avail, the property belonging to the orphans]; and they may not cause her to swear as to what has passed [re her dealings in her husband's lifetime].