Oh absolutely, I thought it was pretty clear that she was always going to go mad, that seemed to be like Chekov's Gun situation... why bring up how crazy they all went from inbreeding if it's not going to play into the plot beyond a long-dead king who was never a direct part of the story since we start into the story when Baratheon is already king. Especially when her brother was clearly pretty mad already. Everyone in her family seems to lose their minds and become awful, it seemed pretty clear that's where it was headed and that's why it was actually important to have her character be played as a "white savior" because she actually isn't.

They did a lot of good setup, but they didn't do enough of actually giving that setup time to properly cook.