Reference for Ketubot 11:2
אַלְמָנָה, בֵּין מִן הָאֵרוּסִין בֵּין מִן הַנִּשּׂוּאִין, מוֹכֶרֶת שֶׁלֹּא בְּבֵית דִּין. רַבִּי שִׁמְעוֹן אוֹמֵר, מִן הַנִּשּׂוּאִין, מוֹכֶרֶת שֶׁלֹּא בְּבֵית דִּין. מִן הָאֵרוּסִין, לֹא תִמְכֹּר אֶלָּא בְּבֵית דִּין, מִפְּנֵי שֶׁאֵין לָהּ מְזוֹנוֹת, וְכָל שֶׁאֵין לָהּ מְזוֹנוֹת, לֹא תִמְכֹּר אֶלָּא בְּבֵית דִּין:
A widow, both from betrothal [in which instance she is not fed (from the property of the inheritance) and she sells her kethubah], both from marriage [in which instance she sells (from the property of the inheritance) for food], sells not before beth-din. [That is, not before a beth-din of experts. But in any event, she must sell before three who are expert in the assessment of land.] R. Shimon says: From marriage, [in which instance she sells (property) for food], she sells not before beth-din, [for she cannot sit and suffer until she finds a beth-din, but] from betrothal [where her sale is only for (collection of) the kethubah], she sells only before beth-din. [The halachah is not in accordance with R. Shimon.]