The 45 year old woman had been given the art work for her ninth birthday but had kept it in her loft for years and forgot about it until she put her house up for sale.
An eagle-eyed auctioneer who was valuing her belongings spotted the oil painting and was stunned when he realised it was by 19th century artist John Everett Millais.
As well as being worth thousands, the dusty painting has also shed light on a 150-year-old scandal of a love triangle involving Pre-Raphaelite artist Millais.
x-posted. Apologies if you've already seen this.