Joseph Edward Thompson, 25, will be sentenced next month after he pleaded guilty to a charge of causing death by careless driving when he appeared at Lincoln Crown Court.
Marian Dixon died on August 12 last year - two weeks after a two vehicle collision on the B1203 at Swinhope on July 28.
The court heard Mrs Dixon was a passenger being driven by her husband when Thompson’s car strayed over the centre white line on a bend and hit their vehicle.
Judge Michael Heath adjourned sentence for the preparation of a probation report and made Thompson the subject of an interim driving ban.
The judge told Thompson: “I reserve this case to myself and impose an interim disqualification which means you must not drive on the public roads.”
Judge Heath added: “The fact I grant you bail does not mean you will not be sent to prison. All options are open.”
Thompson, of Spring Bank, Binbrook, was granted bail until he is sentenced at Lincoln Crown Court on June 2.