'Prominent Guests' Expected at Bill & Melinda Gates' Daughter's Wedding — Inside the Preparations

nayel nassar/ instagram Jennifer Gates and Nayel Nassar

Jennifer Gates' wedding this weekend will be one for the books.

Jennifer, the eldest daughter of Bill Gates and Melinda French Gates, is getting married this weekend to Nayel Nassar in Westchester County, New York, a source tells PEOPLE.

"It will be a big wedding," the source says.

"There is a lot of security, so no doubt there will be prominent guests," the source adds. "Workers have been busy all week. They are setting up both indoor and outdoor areas. They are building several temporary steel and glass pavilions."

RELATED: Melinda Gates Smiles While Spending Time with Daughter Jennifer in N.Y.C. Ahead of Wedding Weekend

Jennifer, 25, has turned to her mother to help her get ready for the big day.

For more on Jennifer Gates' upcoming wedding and other top stories, listen below to our daily podcast PEOPLE Every Day.

"Jennifer is very close with her mom," the source says. "Melinda is a huge part of the wedding preparations."

Jennifer and Melinda, 57, were spotted kicking off the pre-wedding celebrations on Wednesday, stepping out together in New York City. The pair were seen arriving at the Plaza Hotel, where Melinda wore a monochromatic pink outfit while Jennifer donned a white dress.

splash News (L-R) Melinda French Gates and Jennifer Gates

RELATED: What to Know About Bill Gates' Daughter Jennifer's Fiancé, Equestrian Nayel Nassar

"Jennifer and Nayel are both in N.Y.C.," adds the source. "They both seem very excited about their wedding week."

Bill, 65, has also arrived in New York City ahead of the big day. The billionaire Microsoft co-founder was photographed exiting a helicopter with some family and friends on Thursday.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Elder Ordonez/SplashNews.com Bill Gates

Jennifer, who called her parents' separation a "challenging" time for their family, has spent time in recent months with both her mother and father.

Last month, Jennifer attended an outdoor bash in her honor thrown by Melinda to celebrate her nuptials.

"Thank you for this incredibly special celebration, @melindafrenchgates," the Stanford graduate wrote alongside a series of photos, including one of the mother daughter pair.

"So deeply grateful for all the amazing women in my life who advise, support, and uplift me. 🥂 to this new chapter!" Jennifer added.

Jennifer Gates Instagram Jennifer Gates and Melinda French Gates

RELATED: Melinda Gates Is a 'Hero,' Daughter Says in Birthday Tribute After Finalized Divorce from Bill

Jennifer, who is currently an MD Candidate at Icahn School of Medicine at Mount Sinai, also shared a smiling photo with her father back in May.

"Nothing better than quality time with family members," she captioned the snap.