In times of crisis, women have been called upon to actively participate in the front lines of care, and sometimes these moments of serious social and political affectations have become platforms for advancing their rights. Crises, including health crises, bring opportunities to achieve legal gains for women's rights. Based on a reflection of the work performed by women during the influenza pandemic of the early 20th century through the lens of constitutionalist feminism, I propose a discussion of the opportunities and costs that public health crises bring for women. Constitutional feminism allows us to see the dynamic dimension of law, where scenarios such as pandemics generate spaces for participation in agendas where women have been excluded. Historical experience sheds light on how women were able to claim and protect their rights, but it also presents us with an uncomfortable truth about the increase in care work performed by women during health emergencies.