Ambulances crews were called to the Sainsbury's forecourt on Dadson Way at Westwood Cross, Broadstairs, after she collapsed shortly after 3pm on Saturday afternoon.
Police also attended and the woman was taken to hospital in a serious condition after being revived.
An ambulance spokesman said: "Ambulance crews attended Sainsbury’s petrol forecourt on Dadson Way, following reports a woman had collapsed shortly before 3.20pm on 11 November.
"The woman was resuscitated before being taken in a serious condition to QEQM hospital."
"Officers attended the scene where they assisted South East Coast Ambulance Service."