Apologies for the character journal, I'm just now seeing this!

Really the answer to all those are: do as you see fit! Abe/Lucy could have told them about the heart weapons, they could have heard thru the grapevine, randomly learned it, etc etc. So yea she can do an announcement if you want!

Having the flower to be attacked by shadows is totally optional too! Basically you really can't play this event wrong, Utena makes no sense--

Let me know if that answers everything!