But the birth wasn't typical for a royal, as her husband Mike Tindall revealed that Zara gave birth to their third child on the bathroom floor as there wasn't enough time to get to the hospital.
However, thankfully, Zara's friend Dolly Maude was on hand to help safely deliver their little boy – but just who is the royal's best friend?
WATCH: Mike Tindall reveals new feature at home with Zara
Who is Zara Tindall's friend Dolly Maude?
Dolly is a mother-of-four and lives near Zara and Mike with her husband, former jump jockey Chris Maude, in the Cotswolds. She is a trained maternity nurse having worked for the NHS in Gloucestershire for 13 years, according to her LinkedIn profile.
So it's not surprising that she has been present at the births of all three of Zara and Mike's children. Earlier this week, Mike even joked that Dolly is "more important" than he is on his podcast The Good, The Bad and the Rugby.
Dolly has been friends with Zara and Mike for years
Speaking to co-hosts James Haskell and Alex Payne about Lucas' birth, Mike said: "Fortunately Zara's friend Dolly is, she's actually more important than I am at making sure she's been at all three of my children's births, she was there and recognised that we wouldn't have got to the hospital in time, so it was run into the gym, get a mat, get into the bathroom, towels down, brace brace brace!"
Zara and Dolly have been close friends for years and briefly lived together in 2003 after Zara's relationship with her ex-fiancé Richard Johnson ended.
Dolly often joins Zara at Cheltenham with Princess Anne
Dolly was also Zara's maid of honour at her wedding to Mike in 2011 and is often seen with her at Cheltenham Festival.
The pair both share a love of horses, and Dolly even ran Dolly Maude Equine Ltd, a company that rehabilitated injured racehorses with a view to getting them back on the racecourse, according to her profile.
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