Working from home (wfh) has seen a rise in prevalence, particularly in the wake of the COVID-19 pandemic. Although it is widely believed that wfh enables employees to better combine paid work with domestic duties, potentially enhancing work-life balance, emerging evidence suggests that it may also hinder career advancement and adversely affect mental health, with notable impacts on women. We employ longitudinal data from three British Cohort Studies, collected one year into the COVID-19 pandemic, to investigate the characteristics of those who report working from home and the relationship with gender disparities in hourly wages, mental health, and well-being. Using longitudinal data also allows us to control for cohort members' labour market situation prior to the pandemic, thereby helping to isolate the pandemic's effects. Our findings indicate that individuals who work from home typically receive higher wages compared to those who work from employers' premises, but the gender wage gap is most pronounced among those who work from home. Furthermore, consistent with the flexibility paradox, our analysis reveals that women who work from home - particularly those who work hybrid - experience the most detrimental mental health outcomes.