The 2004 continuity just basically took her story from the superman animated series. Bruce Timm and Paul Dini did once before for Mr. Freeze. He'll they should be writing the damn live action movies.
Argo City wasn't destroyed by kryptonite meteors. The ground it sat on was kryptonite but they covered it with lead. Then regular meteors punched holes in it and everybody died, except for Kara, of course.