Gabrielle Union is grateful to be a mother figure.
On Sunday, the Bring It On star, 45, celebrated Mother's Day while reflecting on her difficult journey to motherhood with a sweet video montage of her 2-year-old daughter Kaavia James, whom she shares with husband Dwyane Wade.
"My journey to motherhood was long, arduous and at many times extremely painful," Union wrote on Instagram. "Mother's Day will always be a challenging day to celebrate for me. I know I'm not alone in this feeling. For many reasons, so many of us have a rough time today and to these good people, I send all my love, light and compassion."
"To all the Moms, Stepmoms, Bonus Mom's, Folks who Mother those that need it, Grandma's, House Mothers, I celebrate you today and everyday. Be good to yourselves. 🖤🖤🖤," the actress added.
In her 2017 book, We're Going to Need More Wine, Union previously opened up about her struggles with infertility and failed IVF treatments, writing that she "had eight or nine miscarriages." In November 2018, their daughter Kaavia was born via surrogate.
Wade, 39 shared his own Instagram post to honor his wife on Mother's Day, including an array of snapshots of the happy couple with Kaavia.
"You've shown the world that there's more than one way to be a Mother," the retired NBA star wrote. "Thank you for having the patience and the willingness to learn how to love us. Thank you for allowing us to love you. Thank you for always being with the s----, thank you for always being ready for the antics, thank you for the teaching, the laughter, the sexiness, the coolness, the realness! We love you @gabunion Happy Mother's Day 🖤❤️👑 🌹."
Union responded to her husband's touching post, commenting, "❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️😢😢😢."
In addition to Kaavia, the couple raises Zaya, 13, Zaire, 19, Xavier, 7, and Dahveon, 19, who is Wade's nephew.
Union and Wade told PEOPLE last month all about how they are raising their children to be strong individuals. "My focus when it comes to any of my kids is to let them know who they are so that when other people's opinions about them are formed, it's not hitting them," said Wade.
"If we allow our kids to be their true selves," he added, "we don't have to worry about them conforming with anything or anyone. Why wouldn't we push our kids to be their authentic selves?"
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Shareif Ziyadat/FilmMagic Dwayne Wade, Gabrielle Union
Union explained that in her own childhood, she didn't encounter those same freedoms. "I was raised to assimilate," she recalled. "I was raised to conform. But we are raising our kids to know they are worthy because they exist. We don't want them to ever shape shift for anyone else's approval or acceptance."
"We want them to be free to be who they are," Union shared.
Wade and Union, who wed in 2014, said they lead with love in their parenting. "We want to make sure [our kids] feel strong and supported and free to be exactly who they are," said Union, as Wade added, "What I love about our home is that everybody is unique. And we allow their uniqueness to shine."