“The Ibn Ezra writes that Yitzchak was 13 at the akeidah, which means it would be another 24 years until Sarah died. In that case, all the events mentioned there didn’t occur at the same time, so there is no way of knowing how old Rivkah was at her wedding.”
The Ibn Ezra does not in fact opine on how old Yitzchak was at the time of the Akeida. Rather he comments on what the simple menaing of the word “na’ar” is and says that it normally refers to a lad of approximately 13. But he does not do any of the calculations traditionally done to make this determination.
The Midrash Rabbah states that Yitzchak was 37 at the Akeidah. But it also contains a variant reading in parenthesis of 26, which is consistent with the Seder Olam Rabbah’s statement that Rivkah was 14 when she married.