Khloé Kardashian was inspired to sign her divorce papers by sister Kourtney.

The 36-year-old 'Keeping Up With The Kardashians' star's split from Scott Disick after nearly ten years together prompted the 31-year-old beauty to finally sign her divorce papers to end her marriage to Lamar Odom.

A source told HollywoodLife.com: ''Khloé is sad, but she's feeling strong. Right now, her main focus is being there for Kourtney and the kids. Helping Kourtney through this breakup is giving her a lot of strength - she's in mamma bear mode. It's been a big factor in her finally signing the divorce papers.

''She's been giving Kourtney all this advice about how she needs to be tough with Scott and she realised she needed to take some of her own advice. Signing the paperwork was not easy, but she realised she had to do it.''

Meanwhile, another insider previously claimed that Khloé tried to do everything to save her marriage to the 35-year-old basketball player.

The source said that she even attempted to organise couples therapy for the pair but her estranged husband dished out a number of ''lame excuses'' why he couldn't attend.

In an apparent reference to the decision to formally end her marriage, Khloé thanked her fans for their support, writing on Twitter: ''Such a crazy day!!! Very emotional! Thank you all for being so loving and supportive!!! (sic)''