Rinna, 52, reflected on how hard it was to watch her parents grow older in a blog post on Bravo.
"It's so hard living as far from my aging parents as I do," she wrote last month. "As blessed as I feel to still have both of my parents here on this earth with me, it's hard to know that my dad just doesn't want to be here anymore. I thank God every day, though, that my family, particularly my mother, has such a good sense of humor about life."
"Laughter has helped us get through some pretty tough times together and for that I am grateful. I love my parents dearly, though I think my dad's days are numbered," she continued. "It's just a matter of time now. Please say prayers for him to go peacefully."
The reality TV star thanked fans Thursday night for supporting her through this tough time.