I'd recommend delving a little deeper into her character. The way she clings to her religious beliefs is related to her deep seated existential dread. Jellobell has a great post on the subject on page 2 of this thread and my post on it is on that page as well.
I can see that in her character but it's her stubborn nature which makes her incompatible with any character I might play, though admittly I almost always go with an elf. If I felt like my Dalish elf had a chance to sway Sera's veiws I might reconsider befriending her character, but even if you turn out to be nothing like what she expects a Dalish to be she still veiws all Dalish the same, I would say the same is true of magic even if your a mage.
I'd be perfectly fine with her beliving in the maker, supporting the little people, holding fast with her beliefs if I felt like you had some kind of impact on her. As it is the only way to get along with her is to just agree with everything she wants you to and let her ignore reality. Even some of the common folk recosider thier opinions on elves if your Herald is elvan. I feel that by the end of the game Sera still hates nobles and the dalish just as much as she did before you met her, even though your character is living proof to the contrary.