Maralee Nichols' first Mother's Day was a slam dunk.
A rep for the 31-year-old fitness model—who shares 5-month-old son Theo with Tristan Thompson—told E! News that she and the baby spent "a quiet day together with loved ones" on May 8.
Nichols also shared a sweet image of herself and the baby to commemorate the special occasion.
"Words cannot express how much I love you, being your mommy is my greatest blessing," she captioned the post. "You are my world. Happy Mother's Day to all of the amazing mothers out there!"
Nichols' post comes five months after she filed a paternity lawsuit against Thompson—also father to daughter True Thompson, 4, who he shares with ex Khloe Kardashian, and son Prince, 5, who he shares with ex Jordyn Craig.
In January, the Chicago Bulls star, 31, admitted to being the father of the young boy, writing on Instagram, "I take full responsibility for my actions. Now that paternity has been established, I look forward to amicably raising our son. I sincerely apologize to everyone I've hurt or disappointed throughout this ordeal both publicly and privately."
He also went on to acknowledge the "heartache" he caused Kardashian, 37, following their split last spring.
"Khloe, you don't deserve this," Thompson wrote. "You don't deserve the heartache and humiliation I have caused you. You don't deserve the way I have treated you over the years. My actions certainly have not lined up with the way I view you."
Since the paternity announcement, co-parenting details between the NBA star and Nichols have been relatively private. However, in February, she slammed Thompson for not being more involved in their son's life after an article surfaced claiming that he would pay her $40,000 a month in child support.
In a statement to E! News, Nichols' rep said Thompson "has not made any attempt to meet their son nor has he provided any financial assistance. In the future we hope that reporters covering this situation contact us to confirm any facts before publishing."
Thompson did not publicly address the claims.