Oh, I don't think Alderic will mind Signy actually -- she couldn't exactly help her situation like a normal Apostate Mage, who runs away and/or stays hidden deliberately, aka purposefully defying the Maker and the Chantry. He's not ENTIRELY single-minded or unsympathetic.
Plus, Dwarf Mages are a pretty new thing that he almost certainly didn't receive any training on, so he'd probably just be like, "I--... what is this--... I don't even--..."
Besides, she's too cute to be mad at!
Oh god, I snorted aloud at the Andraste story and "jar full of burned woman". That is amazing. Haha!