Mary Cotter is a real-life Wonder Woman, so for her birthday, her friends decided she should look the part.

The 103-year-old wonder celebrated her birthday at the Montclair Senior Centre in California, where she’s been volunteering for the past 25 years. Her friends bought her a costume to celebrate the occasion because she’s a “real life Wonder Woman”.

At her own birthday party (which she described as “just another day”), she served coffee, tea and water to her friends. It should be noted that Cotter herself doesn’t reside at the Senior Centre — she lives alone and drives herself back and forth to the centre, where she volunteers five days a week. “They call me the barmaid because I serve the drinks,” she told KABC-TV.

Before becoming a superhero, Cotter worked as a children’s swim instructor into her 60s, and helped rescue sea turtles into her 90s. Way back in 1930, Cotter helped her high school win the state swim championship.

When asked her secret to a long and active life, Cotter kept it casual.

“Just keep busy, I guess.”

What do you see yourself doing when you’re 103? Look into your crystal ball in the comments below!