Caitlyn Jenner is reportedly ''excited'' but also ''worried'' about Kylie Jenner's rumoured pregnancy.

The 20-year-old TV personality is believed to be expecting her first child with her boyfriend Travis Scott, but Caitlyn has mixed feelings about her youngest daughter's baby news.

A source explained: ''Caitlyn is excited for Kylie but is also worried and thinks she is too young to move forward with such a big life decision like this.''

Caitlyn, 67, has pledged to support Kylie through her pregnancy, but the former Olympian questions whether becoming a mother at such a young age is a good idea.

In particular, she thinks it could distract the brunette beauty from her money-spinning make-up business.

The insider told Us Weekly: ''Caitlyn is supportive of her daughter, of course, but she doesn't necessarily think this is the right time for Kylie.

''She has a hugely successful business and Caitlyn doesn't want to see that taken away from her.''

By contrast, a source previously claimed that Kylie's family are ''over the moon'' with the prospect of the reality star having a baby.

The source said: ''The family is over the moon! Kylie loves how close knit her family is and is thrilled to bring that to her immediate family. Kylie feels more prepared than ever to be a mom.''

Meanwhile, another insider revealed Kylie had ''always wanted'' to be a young mother.

The source explained: ''Kylie is doing well and is happy. Kylie always wanted to be a young mom. She may be young, but she's very maternal and has lots of practice with babies!

''She's a very hands-on aunt and was basically a step-mom to Tyga's kid. The baby will be very well cared for and so loved. Kylie is excited that her baby will have cousins close to her age too!''