Kourtney Kardashian is reportedly like a second mother to Travis Barker's 15-year-old daughter Alabama.

Kourtney Kardashian

Kourtney Kardashian

The 42-year-old reality star started dating the musician earlier this year, and Kourtney has quickly assumed a prominent role in the life of his teenage daughter.

A source close to the brunette beauty - who has Mason, 11, Penelope, eight, and Reign, six, with Scott Disick - told E! News: "Kourtney has become very close with Travis' kids recently, especially when it comes to Alabama."

Travis, 45, has Alabama and Landon, 17, with his ex-wife Shanna Moakler.

And even though he's only been dating Kourtney for a few months, she's already proven to be a "huge support system" for the teenage duo.

By contrast, Alabama recently discussed her relationship with Shanna in a candid post on social media, suggesting she's not an "amazing mom".

She wrote on Instagram: "My mom has never completely been in my life. Can you guys stop painting her out to be an amazing mom?"

But Shanna, 46, subsequently hit back at the suggestion, insisting she's doing her best for her children amid difficult circumstances.

She said in a statement to People: "Co-parenting is hard, but I have always and will continue to prioritise my children's happiness and well-being."

Shanna also claimed she's been the victim of a "vindictive parenting competition".

But she ultimately hopes that her kids with "see through the fame and money machine".

She explained: "I refuse to involve them in a vindictive parenting competition where feelings are bound to get hurt. Encouraging relationships with both parents is a duty on both mother and father.

"I know one day my children will see through the fame and money machine they have been thrust into and realise their mother loves and will always be there for them."