Old children's book, main character Bara, starts with her death day

The following post was originally posted by jazzycat in 2008, (so hope you don't mind me reposting!) but I am also looking for the same book. I read it about 25 years ago, so it's an oldie, but it has stuck with me and I would really like to get it for my 11 year old. If anyone can help, that would be wonderful! Thanks! :)

'It is Australian.The book's main character is called Bara, and she's in her early teens. She feels different from her peers, and I think she is teased. one day she has a thought in her head that it is her "death Day". Later She has a follows a young boy and ends up in a kind of parallel world, after he tricks her into drinking "Lethe" water. At first she thinks she is in danger but eventually ends up travelling in this place with the boy and his sister. It turns out they can fly.

latter in the book they rescue I think the grandfather from a "Grey City". there is a kind of dream sequence with a jester type character.

I know there was a sequel, and think the title has the word Twighlight in it, but this is all know.

Does anyone out there recognise this?'

The Land Behind The World by Anne Spencer Parry. Bara enters the 'Land Behind the World' as a "Missing Person" and has to fight the Flugs of Grey City. Lots of sequels - Lost Souls of the Twilight is #2.

Thank you so much! Really appreciate the quick response! So look forward to reading this again and sharing it with my kids! :)