Jennifer Garner counts her ballet teacher as part of her family.

Jennifer Garner

Jennifer Garner

The 44-year-old actress, who has daughters Violet, 10, Seraphina, seven, and four-year-old son Samuel with her estranged husband Ben Affleck, has admitted family is "the most important thing" in her life, but insists that doesn't only mean relatives.

Jennifer - who has been named one of PEOPLE's 25 Women Changing the World - told PEOPLE: "Family is the most important thing you could possibly have. But family isn't just your mother, father, sisters, brothers, kids, aunts, uncles, when I go home to West Virginia, I go and see my family.

"And that is my ballet teacher, I go and see my best friend from growing up, her mom, I visited her in the nursing home, and I took my son and we went and saw her, just as if she were my mom. She's so important to me.

"Family is somebody who has just reached outside of themselves over and over to help you and make your life better and with great patience as you have been in enormous pain and I have had a lot of people who have been very patient with me. So I see family as just an extension of yourself, however that may fall in your life."

And the brunette beauty believes motherhood instantly changes someone's outlook on life.

She explained: "Becoming a mother just automatically crosses any boundary you might have with another woman. It's like joining this huge, enormous global club. When you see somebody struggling, you instantly think, 'Well, that could be me.'"

And the '13 Going On 30' star - who is the artistic ambassador for Save the Children organisation - has revealed she is "not afraid to tackle" any situation.

She said: "I might be intimidated to write or I can tackle getting to Mississippi and covering my kids at home ... I can tackle it. I'm not afraid to try. So that's my word and that would be my word of encouragement, to anyone. You can make a difference if you're just not afraid to tackle."