A deadly head-on crash on a Greater Toronto Area highway left grieving family members planning a funeral on their Thanksgiving holiday.

Carol Grimmond, 47, of Windsor, Ont., died Saturday night when the car she was travelling in was struck by a vehicle police say was going the wrong way in the westbound lanes of Highway 407, near Highway 403.

The victim’s twin brother, Colin, was driving the Toyota Corolla that Grimmond was travelling in. He suffered minor injuries.

The adult twin siblings were on their way to their mother’s house in Oakville, Ont., when they were struck by the oncoming car.

No way out

OPP Sgt. Dave Woodford said they had no chance of avoiding the collision.

The siblings’ aunt, Yvette Grimmond, said that the victim’s brother was unable to help his sister after the crash.

"He tried to get her out of the vehicle, but he couldn't," she said.

Police say Carol Grimmond was airlifted to a local hospital where she succumbed to her injuries.

The driver of the vehicle that police allege was going the wrong way was unharmed in the crash.

Police say Mary Sampson, 55, of Oakville, faces now four criminal charges including impaired driving causing death and criminal negligence causing death.

Party preceded tragedy

Yvette Grimmond, said Carol and her brother had attended a birthday party for their grandfather in Vaughan, Ont., before they drove on to their mother’s home in Oakville.

The victim's aunt, Yvette Grimmond, said her family will never be the same after the tragedy that occurred on Saturday night. (CBC)

"It was supposed to be a weekend of happiness, family and Thanksgiving for everyone," she told CBC News in an interview on Monday.

Their grandfather was celebrating his 99th birthday. Now he is upset that his own party preceded his granddaughter’s death.

"He is so saddened that she came for his party…and this happened as she left," Yvette Grimmond said.

Family members spent their Thanksgiving Monday making funeral arrangements.

"My family now will never be the same because of this," Yvette Grimmond said.

With a report from the CBC's Natalie Kalata