Margaret Henderson, from Kirkintilloch, received life threatening injuries in the collision on the A82 on Saturday August 28.
The 77-year-old had been receiving treatment at the Queen Elizabeth University Hospital, but died from medical complications on Wednesday, September 8.
Two men, aged 51 and 76, were also injured in the crash.
Sergeant Nicola Taylor, of Police Scotland’s Road Policing Unit said: “Our thoughts remain with the family of Margaret and enquiries are continuing to establish the full circumstances surrounding this incident.”
Anyone with any information can contact Police via 101, quoting incident number 2591 of Saturday, August 28, 2021.