Ella Travolta / instagram
The 21-year-old actress shared a throwback photo of her mother and herself on Instagram, writing, "Mama, thank you for all you have done for us and for this world."
"I miss you and love you very much, but your smile, warmth and love is ever lasting," she continued. "Wishing all of the moms a happy Mother's Day❤️."
Her dad, John Travolta, left a string of heart emojis in the comments, "❤️❤️❤️❤️," after posting his own tribute to his wife, who died on July 12 after a private two-year struggle with breast cancer at the age of 57.
On Sunday, the Grease star, 67, shared two family photos on Instagram paying tribute to Preston. The first photo shows Travolta and Preston posing in their bed with their daughter Ella and their then-newborn son Benjamin, all dressed in white.
"Dearest Kelly, you brought into my life three of the most wonderful children I have ever known. Thank you. We love and miss you. Happy Mother's Day," Travolta captioned the photos.
The second photo shows Preston smiling while holding the couple's late son Jett with Travolta standing by her side. Jett, the pair's firstborn, died in 2009 after suffering a seizure at the age of 16.
Travolta and Preston were married for 28 years before her death, after tying the knot in 1991.
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The Hairspray actor has spent the past year grieving the loss of his wife in private, working through this "personal journey." Travolta recently told Esquire Mexico that healing has been complicated and the outpouring of support hasn't exactly been helpful.
"The most important thing you can do to help another person when they are in mourning is allow them to live through it and not complicate it with yours," he told the publication in April. "Even though it's great to have company, sometimes it turns into you helping them instead of you working on your loss and grief."
"You have no idea how many people have come up to me … and afterward I've felt saturated with everyone else's pain that I didn't know what to do," Travolta continued, noting that he still appreciates the condolences. "The first thing you should do while going through grief is go somewhere where you can truly mourn, with no interruptions."