Sorry it took me so long to respond, PAA, but the word “b’kolah” in the posuk refers to Sarah’s greater level of nevuah, according to Medrashim quoted by Rashi.
The Medrash says ???? ??? ??? ???? ????? ??? ???? ???????. That does not necessarily translate into “Listen to her because she is a neviah” and it certainly doesn’t say that in the passuk which was all I had said. All the more so according to the Yefei Toar’s pshat that the medrash doesn’t even mean that Sarah had a greater level of nevuah.