The 24-year-old visual artist shared a heartwarming note to Kurt Cobain -- who died in 1994, months before Frances turned 2 years old -- on what would have been the Nirvana frontman's 50th birthday on Monday.
"I love you so much thank you for being my one and only grams," Frances texted. "I wouldn't trade you for the world and I know he is thankful that you raised me to be as strong and compassionate as you are."
"He would be so 'smugly' proud of you, saying 'Hey, that's MY daughter." Frances' grandmother replied. "I love you with all my heart. Thank God you were here for me to love and care for."