She was given the shock of her life after finding out a Rolf Harris painting she owns could fetch �50,000 at auction.

Now Cathy Sims is counting down the days until the portrait of singer Bonnie Tyler, best known for her hit Total Eclipse of the Heart, goes up for auction in West Norfolk next month.

The King's Lynn resident admits she will be 'really nervous' when the artwork goes under the hammer at the Downham Market Auction Rooms on May 16.

She added: 'I'm going to go along on the day but I'm still debating whether to take my little boy Billy. He said he wants to go and because it's our future I think I will take him.

'My only fear at the moment is that it might not go for much at all or might not even sell. I've also never been to an auction before so it will be a new experience to me.'

Auctioneer Barry Hawkins added: 'It could be very busy here on the day and it's going to be very interesting to see how it goes because we haven't sold a Rolf Harris painting before.'

The 42-year-old was given the picture by her father when she was six years old after he bought it for �50 at a charity auction at Sutton Bridge.

She would often sing and dance along to her favourite Bonnie Tyler songs in her playroom which housed the portrait not knowing the artwork's subject was of her favourite childhood singer.

It was only after her father died in 2005 that the mother-of-one decided to research the artwork and discovered it was painted by Rolf Harris and the subject was singer Bonnie Tyler.

She then took the picture to the BBC's Antiques Roadshow when it visited Layer Marney stately home, near Colchester, and was told the portrait was worth up to �50,000.

After the show was aired last year, Miss Sims, who works for Ellab, in Bawburgh, near Norwich, admitted she couldn't afford to keep it because of how much it would cost to insure.

But she quickly started searching for a buyer to sell the painting to for the life-changing sum and help her to fulfil a promise to her five-year-old son and take him to Disneyland Paris this summer.

Philip Mould, an art expert at the Antiques Roadshow, described Mr Harris as a 'young old master'.

Mr Mould told Miss Sims: 'There are people queuing up just waiting for the next Rolf Harris. They're lining the streets in the West End and you have Rolf at his best.'

Mr Harris, 81, who is also known for singing Tie Me Kangaroo Down Sport, has said: 'It's incredible to think that one of my paintings had this impact on someone's life.'

The artwork will go under the hammer at The Auction Rooms, Lynn Road, Downham Market at 1.30pm. Visit www.barryhawkins.co.uk for a closer look a the painting.