Lindsey Thwaites, 51, from South Yorkshire (pictured), says her dog Brian (pictured) helped her discover her anal cancer which caused her to get a stoma bag (pictured in inset).
The EuroMillions website says the jackpot has now reached the maximum of €230 million, or around £191 million - and so cannot climb higher before it is won.
Joe and Jess Thwaite, a couple from just outside Gloucester in their 40s, won the record-breaking £184,262,899 jackpot with a Lucky Dip ticket on May 10.