Background: Women who belong to the age group "emerging adulthood" (18 to 29 years) are vulnerable to mental health issues and suicide-related outcomes. Objectives: This study investigated potential predictors of suicide-related outcomes in females emerging adulthood and compared them to older women. Design and methods: Data of 2537 women from Russia (group "18 to 29 years": n = 1123; group "> 29 years": n = 1414) on lifetime suicide-related outcomes, (problematic) social media use, daily stress, depression and anxiety symptoms, and positive mental health were assessed via online cross-sectional surveys. Results: The younger group spent significantly more time on social media use than the older group. It had significantly higher levels of daily stress, problematic social media use, depression and anxiety symptoms, and suicide-related outcomes. The older group showed significantly higher levels of positive mental health. Only in the younger group, problematic social media use significantly mediated the relationship between daily stress and suicide-related outcomes in a moderated mediation analysis. Positive mental health significantly moderated the association between problematic social media use and suicide-related outcomes. Specifically, the higher the positive mental health level, the less close the link between both variables. Conclusion: The current results reveal that young women in Russia could be at enhanced risk for daily stress, problematic social media use, and low levels of mental health. The interaction between these variables could foster suicide-related outcomes. Public governmental communication in Russia should call attention to potential negative impact of intensive social media use.