Reese Witherspoon is glad she had her children ''kind of young.''

The 'Big Little Lies' star was 23 years old when she had her daughter Ava, 27 when she had her son Deacon, and 37 when she had her youngest Tennessee and she has admitted having a baby is a lot easier in your twenties than thirties.

Taking to her 'Reese Witherspoon x Hello Sunshine' YouTube page, she said: ''I've been a mom since 1999. I got pregnant [with Ava] when I was 22 and delivered when I was 23. To be totally honest, it was scary. I was scared. I didn't know what it was going to do to my job or my career. Your entire life will change. Everything you believe, every piece of food you eat, every piece of independence you have. You can't go out without thinking of another person.

''These are all the things that happen in the beginning, and then it just evolves from there. I find that having little kids is more physical and it's just really hard on your body, so I am glad that I had kids kind of young.

''I had one at 23, one at 27 and then again at 37. And oh my god, having a baby at 37 was so much harder. This is just me being real.''

However, the 43-year-old actress thinks it's important to have a supportive network, regardless of your age and situation, to guide you through parenthood.

She explained: ''I think beyond money, beyond being ready in your career and your life, it's really about, is your support system good? Is your family structure good? Have you talked about it with your partner? Have you thought about it logistically? Like, how am I going to make this work?

''I hope this is helpful. These are the things that a lot of people ask me about. And I also say, if you want to be a mom and that's important to you, you should have every right to do that. And don't put it off because of all the things that seem like a barrier. You're going to figure it out.''

Reese has Ava, 20, and Deacon, 15, with her ex-husband Ryan Phillippe and Tennessee, six, with her husband Jim Toth.