RedheadEmber said: Makes me wonder; how did she know she wasn't supposed to say it out loud? Basic knowledge from the Recognition?
I don't think non-Wolfrider elves know what soul names are until they say or hear them out loud. Consider this:
Winnowill seemed to immediately grasp that the name Lree was Dewshine's soul name. It could be that Tyldak mentioned something about it to her without actually saying the name, because it would have been an alien thing to the Gliders. Leetah herself reached out to Nightfall to try to understand what a soul name was. Even if he didn't, there's no doubt that Winnowill would have identified that Strongbow had such a lock on his deepest self when she was torturing him. So there's a good chance she was already in the know when she heard Tyldak say Lree out loud.