Pregnant but not married

happy in the sense that of she felt she was going to be not married and without a kid versus being unmarried but with a kid.

you are comparing her current situation to what a better situation that could have existed

maybe her frame of reference is the worse condition that she saw in her life or in her future.

obviously at the end of the day, her choice depict her preferences and motivations which we may or may not share or understand, but similarly we then can not gauge her happiness based on our standards either.