Board Thread:TV Show Discussion/@comment-3035448-20170119043310/@comment-5014364-20170119155216

TV-Sansa is going to do whatever the writers think makes her sound cool in a given moment. SDCC 2016, Sophie Turner openly admitted that there was no "reason" for Sansa not to tell Jon about the Vale army; this wasn't her being ruthless and manipulating Jon (as some theorized) it was just to be cool (the writers were sitting there and didn't interject anything).

Sansa isn't a coherent character anymore.