Duchess Meghan "couldn't be a better friend" to Serena Williams.
The 'Suits' actress - who has two-month-old son Archie Harrison Mountbatten-Windsor with her husband Prince Harry - is a great pal to the tennis star through all the "low moments and high moments".
She said: "She couldn't be a better friend to me. Low moments, high moments - she's always there. That's all I want to be to her."
Serena previously revealed she won't give the Duchess of Sussex parenting advice for the first a few months.
The tennis star - who has daughter Olympia with husband Alexis Ohanian - said: "I never pass on words of wisdom because I feel like for everyone - when they have a kid, especially when you just have a baby - it's so difficult to just be. It's just like, 'Get through the first three [or] four months and then we can talk.'"
Despite this, Serena has previously given tips on coping with parenthood for the first time, saying she had to learn to "go with the flow" and adapt to living day-to-day without too much planning to avoid causing unnecessary stress.
She said: "Accept mistakes and don't expect to be perfect. We put so much pressure on ourselves. I had all those high expectations and what I was going to do and then I had what I was going to do. I was gonna recover and I was gonna be great, and this is a time that everything is not going to go as planned. My whole life is so planned and this is the one time where it wasn't. You just gotta go with the flow."
The athlete took on the task of planning Meghan's baby shower back in February for the tot, and has since revealed the party was a lot more pressure than she'd first thought.
She admitted: "Planning something like that takes a lot of effort. I'm a perfectionist, so I'm like, 'Let's make it perfect.'"