"I'm one of seven kids. That'll keep your ego in check"

In this quote, actress Amy Adams is referring to her big family of 7 kids. She suggests that belonging of such a big family has assisted her keep her ego in check. This could suggest that growing up with many brother or sisters has actually taught her the importance of humility and not believing too extremely of oneself. It could also mean that having so many brother or sisters has kept her grounded and advised her that she is simply among lots of, rather than the focal point. In general, Adams is acknowledging the humbling impact that her household dynamic has actually had on her.