Kelly Osbourne made a heartbreaking promise to her dad Ozzy before his death. As Perezcious readers know, the rock legend died last week after a years-long battle with Parkinson's disease. He was 76. His family just mourned his loss on Wednesday by taking part in a teary funeral procession in England. Ozzy was open about not wanting his funeral to be a "mope-fest"... and it sounds like his daughter is taking that to heart. While she's obviously unbearably sad about the loss, she's doing her best to stay strong for her family, including her mom Sharon, an insider told DailyMail.com on Thursday: "The last few days have been a tough ride, but Kelly has been focused on executing plans with her mum." Related: The Osbournes' Touching Fashion Tributes To Ozzy All this leads back to a promise the 40-year-old made with Ozzy, the source detailed: "Of course there have been tears, but she promised her dad - who openly spoke about not wanting people to mourn but rather celebrate his life - that she would not crumble in public." Oof. We know she must be so heartbroken over his passing - and no one would fault her for breaking down during the emotional time! It's totally normal and healthy to feel your feelings, especially at a time like this. But it's also so sweet that she wanted to help ensure that Ozzy was remembered in the celebratory way he wanted. The Black Sabbath singer always "pushed them to 'celebrate what people have done in life, not f**king worry about what's next.'" Kelly is trying to live that way in his honor, though it's a challenge - especially as she worries about her poor mum. Those close to the family are said to be very "concerned about the impact this is having on Sharon," the insider noted: "She and Ozzy were such a unique couple [and] them being apart it is heartbreaking." It's so hard to lose a spouse! And after so long... Thankfully, Sharon has the support of her children, and "Kelly will now be there for Sharon" because of the "very unique bond" she shared with her father. The metalhead-turned-reality star previously told Rolling Stone that he and Kelly were "like two peas in a pod" and even joked that "if I've got a favorite kid, it's Kelly." Wow! They really did have a strong bond! With this in mind, DailyMail's insider went on to note that while Ozzy was seen as a "tough rock star, he was really an emotional teddy bear when it came to the kids." They added: "Ozzy was Kelly's biggest champion in her career and in love. [...] One of his hopes was always that Kelly would find the right partner and fulfil her dream to start a family. For years she had been the doting auntie to Jack's babies and as aunt and granddad they had enjoyed that experience together." We love that Ozzy got to see her welcome her son Sidney AND get engaged to Sid Wilson just weeks before his passing. The source reflected: "When Sid got together with Kelly and they had their son, there was huge joy for Oz." According to the confidant, during some of the No More Tears performer's toughest days, he loved spending time with Kelly and his grandson to keep his spirits up. That special time together only "bolstered the bond" between the family members: "He used to sing to Sidney and play silly games. This was a huge comfort for Kelly, who saw her dad's physical state declining.' Aw. They were all seen together smiling in a video posted just days before Ozzy died. We bet Kelly will always cherish all the quality time they spent together! We're keeping her and the whole family in our thoughts as they continue to process this difficult loss. Thoughts? Share them (below)! [Image via WENN/Avalon & Kelly Osbourne/Instagram] The post Kelly Osbourne's Heartbreaking Final Promise To Dad Ozzy appeared first on Perez Hilton.