The 21-year-old artist - who was just 20 months old when her father, Nirvana rocker Kurt Cobain, committed suicide - told Zelda Williams she will be there for her ''wherever, whenever'' after her actor dad took his own life on Monday (11.08.14).
Frances - whose mother is Hole rocker Courtney Love - tweeted: ''@zeldawilliams You have such an incredibly beautiful soul. I love you but you already knew that. Wherever, whenever u need me I'll be there (sic)''.
Zelda, 25, has released a lengthy statement in tribute to her dad in which she admitted she will ''never, ever understand'' his actions.
She said: ''While I'll never, ever understand how he could be loved so deeply and not find it in his heart to stay, there's minor comfort in knowing our grief and loss, in some small way, is shared with millions. It doesn't help the pain, but at least it's a burden countless others now know we carry, and so many have offered to help lighten the load. Thank you for that.''
Elsewhere in her statement she recalled the last time they spent the day together, thanked fans for their support and told Robin's critics he would be laughing at them.
She also said: ''My family has always been private about our time spent together. It was our way of keeping one thing that was ours, with a man we shared with an entire world. But now that's gone, and I feel stripped bare. My last day with him was his birthday, and I will be forever grateful that my brothers and I got to spend that time alone with him, sharing gifts and laughter. He was always warm, even in his darkest moments...
''To those he touched who are sending kind words, know that one of his favourite things in the world was to make you all laugh. As for those who are sending negativity, know that some small, giggling part of him is sending a flock of pigeons to your house to poop on your car. Right after you've had it washed. After all, he loved to laugh too...
''Dad was, is and always will be one of the kindest, most generous, gentlest souls I've ever known, and while there are few things I know for certain right now, one of them is that not just my world, but the entire world is forever a little darker, less colourful and less full of laughter in his absence. We'll just have to work twice as hard to fill it back up again.''
'Smalls Change (Meditations Upon Ageing)' arrives in April.
The two awards have made for a great 72nd birthday present for the country music icon.