User blog comment:Dryuuu/Why didn't Morgana tell Uther about Merlin poisoning her.../@comment-4190137-20120317011948

Morgana only had one opportunity to tell Uther that Merlin poisoned her. Which was, shortly after her return. If she told him months later, Uther would have suspected something at play, and also thinking of why Merlin would poison her.

But that's a good point! We all know Morgana and Uther. Uther would believe any of the bullsh** Morgana told him, so she would've made up some dumb excuse.