We study how maternal preferences interact with education to shape the motherhood penalty. Using rich Finnish registry data and the quasi-random gender of the firstborn child, we show that mothers across education groups display a mild preference for daughters, reflected in their fertility and parental leave choices. Yet this shared preference translates into divergent long-run outcomes. Ten years after birth, highly educated mothers face a 10\% larger earnings penalty if their firstborn is a son, whereas less educated mothers experience slightly higher penalties with daughters. These differences stem from distinct labor market adjustments: less educated mothers are marginally more likely to exit employment after having a daughter, while highly educated mothers with daughters disproportionately move into public-sector jobs, which offer a relative wage premium. Our findings demonstrate that similar parental preferences can generate contrasting long-term earnings dynamics across education groups, highlighting the role of maternal preferences and labor market sorting in shaping the motherhood penalty.