Natalia shared a photo of herself standing on a football field with Gianna and their sister Bianka. The picture was posted in celebration of Bianka's 4th birthday.
"Happy Birthday B.B Kiddo," Natalia wrote in the caption. "Four Years Old Already....Such A Big Girl Now!"
On her private Instagram account, mom Vanessa Bryant also sent love to Bianka on her birthday, and included Kobe and Gianna in the message.
"Happy 4th birthday Bianka! We love you sooooooo much," the model wrote. "You bring so much sunshine to our days. Thank you. God bless you baby girl. Love Mommy, Daddy, Nani, Gigi, and Koko."
Later on Saturday, Ciara posted pics from Bianka's birthday party on Instagram. The singer included a shot of her and husband Russell Wilson's 3-year-old daughter Sienna Princess Wilson appearing with the birthday girl and her 17-month-old sister Capri Kobe Bryant inside a replica of Cinderella's pumpkin carriage made of balloons, as well as pics of Natalia, Vanessa and La La Anthony.
"Celebrating The Birthday Princess BB's 4th Birthday!" Ciara wrote. "We love you so much! What a magically fun day! @VanessaBryant #Girls."
On Jan. 26, Kobe and Gianna died in a helicopter crash while on their way to Gianna's basketball game. The world mourned the loss of the "Black Mamba," and came out in support of his family during their time of grief.
Vanessa, who married Kobe in 2001, spoke about her husband during a memorial ceremony at the Staples Center, the home of Kobe's former team, the Los Angeles Lakers.
"We loved each other with our whole beings, two perfectly imperfect people making a beautiful family and raising our sweet and amazing girls," she told the crowd of her and her husband. "A couple weeks before they passed, Kobe sent me a sweet text and mentioned how he wanted to spend time together, just the two of us without our kids because I'm his best friend first."
She added, "We never got the chance to do it. We were busy taking care of our girls and just doing our regular everyday responsibilities, but I'm thankful I have that recent text. It means so much to me."
Though this year has been an extremely difficult one for the family, Natalia's post proves that they are sticking together, and remembering the loved ones they lost even during celebratory times.
(This story was originally published on Saturday, Dec. 5, at 2:25 p.m. PT)