Complex sentence: Both Muhammad ibn Abu Bakr and Umm Khultum bint Abu Bakr went to Ali's household after she remarried, but since Aisha had the authority, Umm Khultum bint Abu Bakr married Umar.
Split into simpler sentences: Both Muhammad ibn Abu Bakr and Umm Khultum bint Abu Bakr went to Ali's household after she remarried. Is is said that since Aisha had the authority, Umm Khultum bint Abu Bakr married Umar.