In order to stand against the Revaire Royals or to try to make peace, you have to discovered secrets and made choices with other charcters.
Everyone but widow gets a chance to be neutral, but since the Widow starts on the side of the Revaire Royals/is from Revaire, she can't select being neutral. She has to choose a side, or try for peace.
To only have the one option you have to had missed an essential conversation with Sayra, where you get to pick different options <3