Caitlyn Jenner's daughter Cassandra welcomes third child

LOS ANGELES, Oct. 20 (UPI) -- Caitlyn Jenner welcomed her fourth grandchild this week.

The 66-year-old television personality's eldest daughter, Cassandra Marino, gave birth to her first son with husband Mike Marino on Tuesday.

"He made it! One day before his due date and on Mike's dad's birthday. 8lb 13oz 22 inches long," Marino wrote in a since-deleted Instagram post. "I am elated and exhausted but a super happy non-pregnant mama."

Cassandra Marino and her husband are already parents to daughters Isabella and Francesca. Her half-brother Brandon Jenner is dad to daughter Eva James with his wife and fellow Brandon & Leah singer, Leah Felder.

Jenner shares Marino and her brother, Burt Jenner, with first wife Chrystie Crownover, and is also dad to Brandon, Brody, Kendall and Kylie. Marino told People this month that her relationship with Jenner has improved since the star came out as transgender in 2015.

"My relationship with Caitlyn is much better than with Bruce, but we still have a lot of work to do," she revealed. "We didn't talk for years, and now we see each other every couple of weeks and talk on the phone, which I am grateful for."

"She's happier and more appreciative of her family," Marino added. "She is trying harder and there is a softness to Caitlyn that is new to me. I think part of that is that when someone is happier, they are just nicer."