Re: Should they introduce Kara Zor-El in the sequels?
She could be an ancestor instead of a cousin. An ancestor that has been frozen in stasis and is actually younger than Clark, would make for the same cousin dynamics.
With the way the Man of Steel went along, I would wait until at least a third film before introducing Kara. We need to establish and get Clark himself further down the line for the relationship and presence of Kara to really be effective.