No she is not. Except in the sense that she is perhaps one small step in something that does fitness calculations, but looking at her brain you wouldn't find fitness maximization calculations being done just execution of old adaptations.

These old adaptations encode rough heuristics of limited applicability which approximate fitness calculations (if the environment has been fairly constant for long enough). They are actually there inside the brain. What else do you think the cuteness response as you used here is?

Religious people believe they believe in God. And many of them are correct on this.

Are they? So very few of them actually take their beliefs seriously. So very few of them actually behave as if their expected utility calculations are dominated by treats of eternal damnation and promises of eternal salvation.