It's so hard to tell. I struggled with this myself. The girls are so easy to identify. The boys, I kept second guessing myself. It may just be new leaf growth, but it does look different. Another few days, and you should know for sure. If girls, that white pistil will appear very quickly. At this point, if they are males, it will still be awhile before they are mature enough to drop pollen. Also, the boys often grow their sacs in little bunches as they mature.
Sorry I wasn't much help. I assume you have already changed to the 12/12 light cycle? Just check them carefully every day. They will show their sex more clearly in a few days.
Post new pictures when those growths are a few days older.