Siman 97
Presented here for study, not as a practical ruling. The Shulchan Aruch rules by Sephardi custom, the Rema's glosses by Ashkenazi custom, and the Kitzur follows Ashkenazi custom. For a practical question, ask your rabbi.
א הַמּוֹשִׁיב אִשְׁתּוֹ חֶנְוָנִית, אוֹ שֶׁמִּנָּהּ אַפּוֹטְרוֹפּוּס, מַשְׁבִּיעָהּ אֲפִלּוּ בְּטַעֲנַת שֶׁמָּא שֶׁל שְׁתֵּי כֶּסֶף. אֲבָל אִם אֵינָהּ נוֹשֵׂאת וְנוֹתֶנֶת, אֶלָּא שֶׁמִּתְעַסֶקֶת בְּצָרְכֵי הַבַּיִת בְּפִלְכָּהּ וּבְעִסָתָהּ כְּדֶרֶךְ כָּל הַנָּשִׁים, אֵינוֹ יָכוֹל לְהַשְׁבִּיעָהּ בְּטַעֲנַת שֶׁמָּא:
1 If a man appoints his wife a shopkeeper or a guardian, he may make her swear even in a claim which is unsupported about two silvers. But if she does not do business and only is busy with housekeeping and working with dough, like all women, he is unable to make her swear in an unsupported claim.
ב הַמּוֹשִׁיב אִשְׁתּוֹ חֶנְוָנִית אוֹ שֶׁמִּנָּהּ אַפּוֹטְרוֹפָּא, אֵינוֹ יָכוֹל לְהַשְׁבִּיעָהּ עַד שֶׁתִּתְבַּע כְּתֻבָּתָהּ. וְיֵשׁ אוֹמְרִים שֶׁמַּשְׁבִּיעָהּ כָּל זְמַן שֶׁיִּרְצֶה. יִחֵד לָהּ קַרְקַע בִּכְתֻבָּתָהּ, אַף עַל פִּי שֶׁבָּאתָה לִגְבּוֹת כְּתֻבָּתָהּ לָא מִקְּרֵי תּוֹבַעַת כְּתֻבָּה, וְאֵינוֹ יָכוֹל לְהַשְׁבִּיעָהּ (מָרְדְּכַי פֶּרֶק הַכּוֹתֵב) לְפִי סְבָרָא הָרִאשׁוֹנָה:
2 A man who appoints his wife as a shopkeeper or a gaurdian, cannot make her swear until she claims her ketubah. And some say that he can make her swear any time he wants. If he designated land for her in the ketubah, even if she came to collect her ketubah, it is not called claiming her ketubah and he cannot make her swear (Mordechai Ch. Hakotev) because of the first reason.