Amanda Seyfried is notoriously private when it comes to sharing images of her children, but there was one photo this week that the actress just couldn't resist sharing.The Mamma Mia actress took to her Instagram Stories and shared a sweet snap of her daughter Nina wearing a Little Mermaid shirt and a really sweet Elsa face towel over her face. The 35-year-old mother-of-two has been rigorous in keeping her children's identities out of the spotlight.WATCH: Mean Girls is trending on Netflix after