Let's say a husband and wife are alone on Friday night or on Shabbos day. Can the wife make kiddush for herself and her husband?
Since women are obligated in kiddush on a Torah level (Zachor>Shamor), they can make kiddush for their husbands. The Aruch haShulchan 271:5 rejects the idea that women should not cover men, limiting it to public venues (b'tzibur).
That said, I once went to someones house where the woman made hamotzi. It rubbed me the wrong way. Since the custom has been for the man to do kiddush, it seemed like they were making a statement that should be outside the Jewish purview.