Brandon Jenner's mum, actress Linda Thompson, teamed up with Leah's mother, Susan Felder, wife of Eagles guitarist Don, to throw the outdoor bash at the couple's California home.

Thompson shared photos of the party with fans on Instagram.com, but the sex of the baby was kept a mystery as they used pink and blue decorations for the family event.

In the caption for a video clip of the baby shower set-up, she wrote, "Imagine my joy & gratitude that @brandontjenner & @leah_jenner are blessing our family with a baby soon. Leah's mom & I are throwing this delightful baby shower for them at their home. It reflects all the warmth & beauty their souls embody. #thankyouGod (sic)".

The couple, which performs as musical duo Brandon & Leah, wed in 2012 and announced its baby news in March (15).

The child won't be the only new addition to the Jenner/Kardashian clan - Brandon's stepsister, Kim Kardashian, announced she is expecting her second child with husband Kanye West on Sunday (31May15), at the end of the latest episode of her U.S. reality TV show, Keeping Up With the Kardashians.