Yorick's maiden does not attack inhibitors

I had a game today, I was playing Yorick. At one point enemy top lane tier 1 and 2 turrets were down, inhibitor turret was at 1/2 HP. I let the Maiden + ZZ'rot push the lane, while I joined my team in a fight. She destroyed the turret, but instead of continuing and attack the Inhib she started awkwardly wandering around, ending up fighting the midlane minions. Not sure if that is a bug or intended feature, but it felt pretty disappointing. I feel that the maiden is supposed to be useful as a split-pusher herself (maybe not the best use, but still an option), but not being able to take down inhibitors ruins that big time.