I read it in the late 80’s early 90’s at school. All I can remember was a boy who finds a knife/dagger in a stone down by a beach. when he pulls it out he becomes a ghost. That’s all I can remember. Any ideas?

I’m just jumping on because I’m looking for it too and adding a few extra details. I specifically remember she wanted to live in a castle and the boy teased her for loving ina tine flat and made fun of her singing/saying something like “(girl) lives in a teeny tiny little flat, not even enough room to swing a cat!” And by the end of the party after seeing her transformed flat (the parents moved all the normal furniture into their bedroom from the lounge room and taped over the keyhole so she couldn’t peek before the party and let her sleep on a mattress on the floor that night after the party) the boy said it was the best party/day ever and they were friend after. The book was gifted to me by my grandmother around 99/00(so it was still in print by then) and was my absolute favourite but around 05 my little brother was pissed at me about something and hid my book under the fridge to get back at me and because the fridge was really old and leaking fluid the book got soaked in gross stuff and ruined beyond repair and I was devastated. I have literally every other book from my childhood (English teach as a mother made sure we took really good care of our books ) and my son now has them and we read my old books almost every night. I would love to have a new copy of this book to read to him but have been unable to find it. I know it was called either “Castle In The Sky” or “The Little Castle In The Sky”, but after 20/30 years it could have a new title if it’s still in print.

Possibly The Wait-for-Me Kitten. It was a Little Golden Book. The other kittens run away and the smallest kitten always shouts, “Wait for me!” But they never do. One day the kittens make a mess and the smallest kitten is left behind. Instead of getting in trouble the smallest kitten helps clean the mess and gets a treat as a reward.