Conversely, the two surviving Kryptonians escaped their planet's fate in different ways: one was rocketed to Earth, whereas the other was "safely" imprisoned in the Phantom Zone.

Source: https://www.cbr.com/superman-mirror-image-villains-dc/

Or the show could always throw a curveball and have Lara be alive and in stasis or even residing in the Phantom Zone.

Source: https://www.cbr.com/my-adventures-with-superman-season1-unanswered-questions/

’s version of Superman’s doppelganger Bizarro is naturally portrayed by Tom Welling, and is another wraith from within the Phantom Zone.

Source: https://screenrant.com/20-kryptonians-smallville-not-clark-kent/