Reference for Yevamot 210:14
צריכי דאי איתמר הך קמייתא הוה אמינא ה"מ לכתחילה אבל דיעבד אפי' תרי קמ"ל אין הלכה כאותו הזוג ואי אשמועינן אין הלכה כאותו הזוג אלא כתנא קמא ה"א דיעבד אבל לכתחילה ליבעי חמשה צריכא:
Raba said: [She must wait with <i>halizah</i>] until she has reached the age of [valid] vows.<span class="x" onmousemove="('comment',' One year prior to puberty, or the age of eleven years and one day, when her vows and consecrations are valid if on examination she is found to understand their significance and purpose. (Cf. Nid. 45b). ');"><sup>34</sup></span> The law however, is [that she must not perform <i>halizah</i>] until she has produced two [pubic] hairs. IF [A SISTER-IN-LAW] PERFORMED <i>HALIZAH</i> IN THE PRESENCE OF TWO etc. R. Joseph b. Manyumi stated in the name of R. Nahman: The <i>halachah</i> is not in agreement with this pair.<span class="x" onmousemove="('comment',' R. Simeon and R. Johanan ha-Sandelar, the halachah being in agreement with the first Tanna who maintains that three judges are required for a halizah. ');"><sup>35</sup></span>