Sam Elliott's only daughter, Cleo Rose, celebrated her 39th birthday on September 17 alongside her parents and fiancé. The actress, who is also a musician, uploaded several photos from the birthday gathering on her Instagram page, capturing fans' attention. The first two images showed the celebrant posing at a beachfront restaurant in a lovely dress, while another featured a selfie with her fiance, Jacob Rosenbaum. The last photo had Cleo's parents, Sam and Katherine Ross, smiling together. The singer simply captioned the photo "39" with a cake emoji. Fans admire Sam and Katharine Instagram While many users wished Cleo a happy birthday, others noted how beautiful her family looked, especially her parents. "Your parents are wonderful!" someone exclaimed in the comments. The elderly couple have been married for thirty-nine years, making theirs one of the longest-lasting celebrity marriages in Hollywood. RELATED: Sam Elliott Shares How He Met John Wayne During Wayne’s Final Film Sam and Katharine share a beautiful bond, which they have proven on several occasions. In February, Sam gave a shout-out to Katharine as he received his SAG Award for Best Male Actor in a Television Movie or Limited Series. "My beautiful Katharine, my partner through thick and thin, and the mother of our beautiful daughter," he acknowledged as he accepted the award for his role as Shea Brennan in 1883. Instagram He has a great relationship with his daughter, Cleo Sam is not only a loving husband, but he is also a hands-on dad. Every now and then, he's gushed about Cleo and his fatherly love for her. In 2017, the proud dad revealed they have a "deeply loving relationship" and see each other a lot. He added being a father to Cleo has been more fulfilling than achieving his lifelong dream to be an actor. "It completes me," he said of fatherhood. Instagram Beyond her dad, Cleo has also found love in the arms of fiancé Jacob. For her birthday, he shared several photos of them, writing on Instagram that he could not wait to marry Cleo. In May, Jacob confirmed their engagement by hinting she was his fiance with a hashtag. Judging from the recent birthday posts, he seems to get along quite well with the celebrity family.