All of the Details on Scheana Shay's Surprise Engagement Ring Upgrade from Husband Brock Davies

Scheana Shay Instagram; Amanda Edwards/Getty Images

Scheana Shay had a big surprise waiting for her at the altar.

Brock Davies presented his Vanderpump Rules bride with an upgraded engagement ring during the couple's romantic nuptials in Cancún, Mexico on Aug. 23.

Designed by Ring Come True, Shay's new addition is a 4-carat emerald cut solitaire engagement ring, according to an Instagram post shared by the jeweler. The stone sits on top of a thin diamond band.

The sparkler complemented Shay's show-stopping custom wedding gown (the dress was made with a removable overskirt for a new reception look) designed by Gown and Out in Beverly Hills star Pol' Atteu.

"I love that we have designed this from scratch together and the lace is absolutely stunning," she told PEOPLE exclusively.

RELATED: Scheana Shay and Brock Davies Are Married! Inside the 'Vanderpump Rules' Couple's Mexico Wedding

For her afterparty look, the 37-year-old reality star changed into a white strapless minidress from Newport Beach-based Casablanca Bridal, which she teamed with a dazzling headband and high-top platform sneakers.

Wedding guests included VPR co-stars Ariana Madix and Raquel Leviss, who participated in Shay's bridal party, and Tom Sandoval and Tom Schwartz, who were two of Davies' groomsmen.

"The fact that that many people came on vacation with us is so cool," Shay told PEOPLE on the ceremony. "I feel like it's a small wedding in scale, but it's big for a destination. I want this special moment. Brock deserves this. We deserve this."

In July 2021, Davies originally proposed to Shay in their Los Angeles home with a 12.74-carat rectangular cushion-cut rare fancy pink morganite ring on a 14-karat, 12-diamond white gold band designed by Kyle Chan.

"Scheana and I have talked openly about what we want in life, all the way down to the ring. So all I needed to do was talk to our good friend Kyle Chan, who also happens to be an amazing jeweler," Davies told PEOPLE exclusively. "He ran with the design and came back with such a fire cut."

RELATED: Get a Close-Up Look at Scheana Shay's 'Rare' 12.74-Carat Pink Morganite Engagement Ring

Although cozy and intimate, the at-home occasion was executed in style. Shay tapped into bridalwear with a white, high-slit dress with a corset bustier and nude pumps while Davies went traditional with a white button-up and black trousers.

Emma McIntyre/WireImage

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The couple's relationship tracks back to Fall 2019, when they first started dating after meeting each other through mutual friends. At the time, a source revealed to PEOPLE that Shay "hasn't seemed this genuinely happy in a while."

In April 2021, the two welcomed their first daughter Summer Moon on Instagram, Shay writing that herself and Davies were "feeling all the feels and just so excited to be Summer's parents!!!"

RELATED: Scheana Shay Says Daughter Summer Moon Has 'Changed My Life' as She Celebrates First Mother's Day

She also updated fans on her health, announcing that she was diagnosed with Preeclampsia, which later developed into HELLP syndrome. "My doctor said I was lucky, and we caught this just in time to treat as it's very unusual to be caught so late, in postpartum," Shay wrote, adding that she was being monitored "closely" for "elevated liver enzymes and low blood platelets."

Davies shared his own Instagram photo writing, "Baby mamma is doing great, baby and daddy are holding down the room for mamma...... Thank you everyone who reached out and the amazing staff."