J.K. Rowling worries she'll die before she finishes writing her new children's books.

J.K. Rowling

J.K. Rowling

The 50-year-old author is busily working on new material and revealed she has "so many ideas" to put down on paper - but the 'Harry Potter' writer fears she won't have the time to realise her ambitions.

She said: "I sometimes worry I'll die before I've written them all out. That's my midlife crisis - that I will leave this earth without having written them all."

The award-winning writer also announced plans to return to the professional name of J.K. Rowling, having written some of her more recent work, including the crime novel 'The Cuckoo's Calling', under the pseudonym of Robert Galbraith.

She told BBC Radio 2: "I have plans to write novels - in the plural - as J.K. Rowling again but I'm not going to give you an absolute date because things are busy enough.

"I have an idea for a children's book, which I really love - I've been writing part of a children's book so I'm going to finish that - and I have ideas for other adult books."

As well as writing new children's stories, she has also penned a film adaptation of her 2001 book 'Fantastic Beasts and Where to Find Them', with Oscar-winning star Eddie Redmayne having been cast in a lead role, as well as a new stage production titled 'Harry Potter and the Cursed Child'.