Sofia Richie sister and father, Lionel Richie never supported her relationship with Scott Disick

The 21-year-old's famous older sister 

Nicole Richie, as well as their music legend father Lionel Richie, never supported her relationship with Disick, 37, according to Us Weekly.

Scott and Sofia have split after Scott's recent stint in rehab. 

As an insider revealed, the House of Harlow fashion designer, 38, 'never fully supported' her baby sister's relationship to the much older Disick, which 'played a big role in their issues.'

'Nicole and Sofia have been spending more time together since Sofia started spending less time with Scott,' the source also said.  

'Nicole has always been a rock for Sofia,' and 'wants the best and healthiest outcome' for her, they added.

Scott Disick and Sofia Richie

'Sofia noticed that he wasn’t doing well and gave him an ultimatum, and in the end it seemed like Scott was more focused on Kourtney and his kids than her,' a source said.

Scott recently celebrated his 37th birthday without Sofia, and instead was joined by Kourtney and their three children in Lake Powell, Utah.