If HIB didn't create any new queens in Alera then could she coordinate the sieges that are going on all over the Realm (Rhodes, Acquitaine, Forcia, Attica). I suppose she could have given them simple instruction, but wouldn't they easier to defeat without a queen present?
Well, in Princeps when Tavi is examining the Vord expansion, he figures the whole thing out by the delayed "waves" of assault that show the orders being relayed to the front by the Vord queens...that could be happening in Alera as well, with the Queen flying in to take over the final assaults, when necessary.
For me, the comment of the sterile Vord queen stating that HIB (first queen - the non-sterile one) was not acting normally by not creating queens that could reproduce is the only reason that I am guessing that she has not created more - and it is that, just a guess...