Julia Stiles and husband Preston Cook secretly welcomed their third child five months ago.
The 43-year-old actress revealed she and Preston - who tied the knot in 2017 - quietly added to their family last year.
Speaking to The New York Times, she said: "“I’m kind of like a bundle of emotions, because I have a five-month-old baby and I went into directing my first movie.
"I didn’t really talk about it. I think that actually being a mom is really great training for being a director. You have to think 10 steps ahead but also be in the present moment. You have to be good at time management. You have to be sensitive to people’s needs and guide them, but also hold a boundary."
Julia already has a two-year-old son and a six-year-old son with Preston and admitted that life as a mom of three and a first-time director on the movie 'Wish You Were Here', has left her exhausted.
She said: "I am running on fumes in terms of sleep. “But I [have more energy] than I ever have."
One of Julia's best-known roles is as heroine Kat in '10 Things I Hate About You' and she admitted she rebelled against the success of the 1999 movie by going to college.
She said: "How did I handle it? I sometimes imploded. I also rebelled against it, probably, by running in the other direction a little bit.
"I went to college so that I could focus on other things. I would take time off from work … to not give it as much power. I know that I was thinking: I don’t want to be sitting around at 40 with a bunch of studio executives or other people that have had that experience and I didn’t.
"As a performer, to be in something that people are talking about 25 years later is very special and very meaningful.”