She thinks it's a terrible idea

Mother is looking very severe. "What could have possessed you into this?" she asks. "Mother," you entreat, "the bastion of our faith is under threat. It is only right that we move to defend it." Mother is having none of your excuses. "Then you could have sent money, or hired some mercenaries!" Her voice has raised almost to yelling. Sophie silently winces at her rage. "But no, you have to go on campaign, in person! You, the last male of your line." She looks at you harshly, daring you to snap back at her. "It's not just that mother. Princess Cateline is available for marriage, and she could be an excellent match. I would have to see her in person, for I will not be married by proxy! Furthermore, if I were to tie myself and our dynasty to the Kingdom, I would want an on-the-ground assessment of its situation first. Raymond acts like he has the situation under control, but I have my doubts. As you can see, I am not doing this simply out of fervor mother." Your reasoning seems to make an impact on her. She looks like she just swallowed a biting comeback, and it tasted bad.

"Very well my son, I see you've settled on your path. It's just, your choice is so dangerous. Can you imagine the chaos if you are killed, leaving no heir? And warfare is not the only danger. Hunger, thirst, disease; all may kill just as effectively as the sword. But I know this will not dissuade you. Go on your fool's errand, I will not stop you." You move forward to hug her, trying to make peace. She hands your infant sister off to Sophie and accepts your hug, though you can feel her sob quietly into your shoulder. The two of you exchange words of love for the other, and you turn to go. "Wait just a moment son!" she calls out.