Susanne Hinte, 48, is said to have been in "floods of tears" since apparently discovering that she had picked the winning numbers and will now have to wait until July to hear whether lottery operator Camelot will pay out.
Miss Hinte, who lives in a rented, three-bedroom semi-detached home in Warndon, Worcester, one mile from Ambleside News where she claims she bought the golden ticket, is said to have not slept since finding it in the pocket of her newly washed jeans.
Her daughter Natasha Douglas, 28, a shop assistant at Morrisons, said her mother, who has a heart condition, was far from celebrating.
She said her mother had not initially checked her numbers when the draw was announced because she had been "distracted" looking after her grandchildren.
"So she searched the house and I got a phone call from her saying she'd got the winning numbers. When she found out she couldn't breathe and she hasn't slept since."
She said her mother had already received begging letters from people after her details came out on Facebook.
On January 9, two tickets matched the biggest jackpot ever of pounds £66 million. One half was won by David and Carol Martin, both 54, from Hawick in the Scottish Borders, while Camelot is examining Miss Hinte's claim that she bought the other winning ticket but accidentally put it through the wash.
While her ticket had the right combination of winning numbers - 26, 27, 46, 47, 52, 58 - the water had scrubbed away the date, as well as the corresponding barcode and all-important serial number.
She has been advised to send in the ticket with as many details as possible about where it was purchased.
"Without a serial number, almost more important than a ticket are the details surrounding its purchase, exactly when it was bought, what time, where, whether it was a lucky dip," a spokesman for Camelot said.
Even if Miss Hinte's claim is verified she will have to wait months. Camelot said they expected several more claims to be made on the money before the July deadline and they would only then reveal if any were legitimate.