User blog comment:Curtis712120/Earth-3/@comment-28458080-20160623042720/@comment-27700324-20160623140223

No, Kara said she didn't know who the Flash is, not that their isn't one. Barry said that there is a Central City, and during the S1 finale, Non said he was going to conquer Central City and Opal City next. Point is there could be a Flash that Barry didn't find out about when he was on Kara's Earth for just a short afternoon.