Denise Richards reveals 9-year-old daughter said 'dad' for first time

It was an extra special Father's Day in Denise Richards' household!

The "Real Housewives of Beverly Hills" star revealed her 9-year-old daughter, Eloise, who lives with Chromosome 8, Monosomy 8p, a rare chromomal disorder, recently said "dad" for the first time.

"Happy Father's Day to my dad you are the best dad ever. Thank you for always being there & being an amazing role model. I love you so much," she wrote on Instagram. "And happy Father's Day to my beautiful husband I can't imagine a better father for our Eloise & step father for sami & lola. I love you so much. And the greatest gift Eloise being able to say "dad" for the first time a month ago."

Richards adopted Eloise in 2011 as a single mother. She revealed during the "Real Housewives of Beverly Hills" Season 9 After Show that her husband, Aaron Phypers, planned to adopt Eloise.

The actress has also been candid about the challenges Eloise deals with as a result of her condition.

"It's caused many delays with her and it's caused a lot with speech, development," she said during the "Real Housewives of Beverly Hills" Season 9 reunion. "We found out probably two years ago exactly. It was a very difficult thing to diagnose, she went through a lot. It was really hard when I saw what was written on the medical report to get the blood test and all the testing done. It was hard to see it in black and white, to be honest."