'Excited' Jennifer Gates Preps 'Big Wedding' to Nayel Nassar with Mom Melinda's Help, Says Source

Nayel Nassar/Instagram Jennifer Gates and Nayel Nassar

Jennifer Gates is getting ready to walk down the aisle!

The eldest daughter of Bill Gates and Melinda French Gates spent time with her loved ones on Wednesday ahead of her wedding to fiancé Nayel Nassar in Westchester County this weekend, a source tells PEOPLE.

"They kicked off the celebrations yesterday in N.Y.C.," the source says of Jennifer, 25, and the equestrian, 30. "Jennifer was with her family and friends yesterday and Nayel with his. They both seem very excited about their wedding week."

The insider says Melinda, 57, has been helping her daughter get ready for the big day.

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

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

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

Last month, Melinda threw an intimate party for her daughter, which was attended by a number of important women in Jennifer's life.

"Thank you for this incredibly special celebration, @melindafrenchgates," Jennifer wrote alongside a series of photos from the outdoor bash.

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

Jennifer Gates Instagram Jennifer Gates and Melinda French Gates

The Stanford graduate, who is currently an MD Candidate at Icahn School of Medicine at Mount Sinai, announced her engagement in January 2020.

"Nayel Nassar, you are one of a kind. Absolutely swept me off my feet this past weekend, surprising me in the most meaningful location over one of our many shared passions," she captioned a sweet shot of the pair.

"I can't wait to spend the rest of our lives learning, growing, laughing and loving together," she added. "Yes a million times over."

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"I'm feeling like the luckiest (and happiest) man in the world right about now," Nassar, who competed at the Tokyo Olympics this summer as part of the Egyptian team, captioned his own post. "Jenn, you are everything I could have possibly imagined..and so much more. I can't wait to keep growing together through this journey called life, and I simply can't imagine mine without you anymore."

"Love you more than you can possibly imagine, and thank you for making every single day feel like a dream to me," he added. "Here's to forever!"

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

Nassar attended Stanford with his future wife, whom he began dating in January 2017.

Jennifer is also an accomplished equestrian and the founder of Evergate Stables. Their love for the sport was part of what bonded them together.

"Horses are just one part of our life, but we love the sport," she told CNN's EQ equestrian show in 2019. "He's a professional, and I do this as an amateur. So, to be able to share our love and passion for horses with each other is just incredible."