SHE made the ultimate bridesmaid, but in less than a week Pippa Middleton will take centre stage at her own lavish wedding.

On May 20 she will walk down the aisle to marry hedge fund manager James Matthews, six years after wearing that incredible bum-hugging Alexander McQueen gown at big sister Kate’s nuptials.

Pippa, 33, and James, 41, will exchange vows in front of 350 guests at the 12th century St Mark’s Church in Englefield, Berks. It is estimated the society ceremony of the year will cost £250,000 (AU$463,500) — 10 times the UK average.

Here’s all you need to know about Pippa’s almost-royal wedding.

Source: SheinDressAU

The family and the best man

Pippa’s new in-laws are a colourful bunch. James’s glamorous mum Jane, 69, had a bohemian upbringing in Zimbabwe before studying at Rhodes University in South Africa.

She met James’s dad Dave after he spotted her picture in his sister-in-law Lu’s Rhodes University yearbook and immediately asked for her number.

On their first date he turned up in a Ferrari Daytona, and Jane was bowled over. But their wedding was a more simple affair — at a register office with Jane in a brown sweater and skirt.

Perhaps it would have been different had they already made their millions transforming the Eden Rock Hotel, on the Caribbean island of St Barts, into a celebrity haunt.

James is the oldest of their three children. One of his brothers, Michael, tragically died at the age of 22 in 1999 while climbing Everest.

His other brother, Spencer, is well known for being on reality TV series Made in Chelsea.

It is believed the infamous womaniser — who has boasted of more than 1,000 conquests — will be the best man.

Spencer, 27, has been dating model Vogue Williams after meeting while they both appeared on reality telly series The Jump.

He was axed from I’m a Celebrity in 2015 after he confessed to a steroid addiction. He has also spoken of taking cocaine and having six-in-a-bed orgies.

The guests

Despite rumours that Pippa planned a “no ring, no bring” policy — meaning no unmarried plus-ones — Prince Harry’s American girlfriend Meghan Markle, 35, has been invited.

Pippa has also bent the rule for her brother James’s girlfriend, former TV presenter Donna Air, 37. She will be bringing her teenage daughter Freya, whose father is casino and zoo magnate Damian Aspinall.

But model and reality star Vogue Williams, who is dating Pippa’s future brother-in-law Spencer, has been axed from the invites.

The gaggle of Pippa’s plummy-voiced posh pals will include Alice St John Webster, who she went to Marlborough College with, and Camilla Campion-Awwad, an Edinburgh University friend.

Along with Pippa’s parents, Michael and Carole, sister Kate and Wills, other family guests will include fiance James’s nieces, Lily, 17, and Rosa Mackie, 15.

And if their love of social media selfies is anything to go by, the teens will grab their fair share of the attention.

Celebrity friends believed to be attending the wedding include tennis star Roger Federer, his wife Mirka and TV explorer Ben Fogle.

The bridesmaids and page boy

While Pippa took on bridesmaid duties for sister Kate, it is unlikely the Duchess will return the favour for fear of stealing the limelight.

Royal correspondent Judy Wade said: “It’s a tricky situation for Pippa.

She would want her sister by her side but if your sister is a future queen, she is going to upstage the bride.

“Kate would want to be in the background.”

It is rumoured that Kate has offered to look after the children and give a reading.

Royal-watchers predict that Princess Charlotte, two, will be a flower girl and that three-year-old brother Prince George will be a page boy or ring bearer.

Tallulah Goldsmith, 14, daughter of Pippa’s uncle Gary, is almost certain to be a bridesmaid.

Gary has been kept at arm’s length by the Middletons since being caught with cocaine by an undercover journalist at his Ibiza party pad, Le Maison de Bang Bang.

It is thought the move is Pippa attempting to heal the rift.

The diet

Everyone wants to look their best on their big day, but how will Pippa top her appearance as a bridesmaid at Kate’s wedding?

She has been spotted leaving the exclusive KX Gym in Chelsea where she has been fitting in pre-wedding workouts.

And it is rumoured she is following the Sirtfood Diet.

The meal plan, advocated by her former personal trainer Pete Geracimo, involves sticking to a diet of 20 foods that activate proteins in the body called sirtuins.

Researchers believe sirtuins influence the body’s ability to burn fat. Luckily for Pippa, these foods include dark chocolate and red wine.

The plan begins with a three-day period of 1,000 calories a day, made up largely of green juices and one sirtfood meal.

Calorie intake then rises to 1,500, with two sirtfood-rich meals a day.

The dress

Designer Giles Deacon was spotted visiting Pippa and her mother Carole just before Christmas, holding a garment bag.

However, Giles, 47, says: “I can never really comment on rumours. Until things are confirmed, it’s rumours.”

A couture dress from a designer such as Deacon could cost upwards of £50,000 ($AU87,257).

Commenting on Pippa’s likely style choice, one source said: “No puffballs, but she adores lace and long sleeves.

“There won’t be too much embellishment. It will show off her amazing figure.”

Milliner Stephen Jones has also been seen leaving Pippa’s house. He was carrying a huge bag — so a spectacular head dress and veil may be in the offing.

The hen bash

Pippa was joined by sister Kate for a secret hen do in the French resort of Meribel in March.

The low-key celebration took place on the same weekend that Prince William was pictured “dad dancing” and chatting to a glamorous blonde model on a lads’ break 160 kilometres away in Verbier, Switzerland.

The venues

The pair will tie the knot in a 12th-century church near Bucklebury, where Pippa grew up.

St Mark’s in Englefield, Berks also played host to Prince William, Kate and their children last Christmas Day.

It is understood that, if there is room, local parishioners have the right to attend the wedding ceremony as it is a public service. However, this is only “unless a genuine question of safety or security arises”.

The church is situated in the grounds of Englefield House, where a formal drinks party will be held after the service.

The stately home has featured in the films The King’s Speech and X-Men: First Class, as well as TV series The Crown.

The evening reception will be down the road in a marquee on the lawn of the Middleton’s home, with a sit-down supper from caterers Admirable Crichton.

A source said: “It will be blingtastic — the best champagne and a special champagne cocktail”.

The invites

In a sweet, understated move, Pippa and James sent their save-the-date notices inside their Christmas cards.

It is thought the invitations have come from Mount Street Printers, which was awarded a Royal Warrant in 2011, as Pippa and mum Carole have been seen at its London shop.

The flowers

It looks like Chelsea’s Lavender Green Flowers has landed the big wedding contract, with Pippa making regular visits to its West London store.

While Pippa has been keeping quiet, according to sources she’s picked a trio of royal colours — red, white and blue — made up of peonies or hydrangeas.

This article originally appeared on The Sun.

Also see: bridesmaid dresses