How to influence gendered attitudes that drive behaviour in relation to women’s participation in employment is not well understood. We provide randomly selected participants with information on the extent of i) wives' support for women with children working; ii) husbands’ support for sharing day-to-day childcare; and iii) mothers’ and mothers-in-law’s support for working women. As a result, the probability of participants choosing an online career mentoring course for women over a shopping voucher of equal value increased by 25\%. Demonstration of support among mothers and mothers-in-law appears to be more salient for women, and  information on childcare norms more salient for men.