The daughter of a desperately-ill American woman has admitted that she came to Alberta as part of a suicide pact with her mother.

In a surprise move Tuesday morning, Linda McNall pleaded guilty to one count of assisted suicide after helping her mother Shirley Vann kill herself while the two were camping at Rock Lake, near Hinton.

“They sold everything to make this one last trip together,” said Laura Stevens, McNall’s laywer.

Vann was suffering from colon cancer, and Stevens says her client has lost all hope.

“[She] lost it because she was losing her mother. And watching her mother suffer. She just couldn't do it anymore. And made a decision to end their lives together - along with their dogs.”

The pair travelled to Rock Lake because both thought it was one of the most beautiful places on earth.

There, they each signed a letter saying that they were taking their own lives.

Then they both injected themselves with an overdose of insulin, opened a propane tank in their tent, took sleeping pills and laid down to die.

Shirley Vann stopped breathing the next day, as did the dogs that the pair owned.

But Linda McNall survived.

“She was my whole life”

McNall drove the body of her mother to the hospital in Hinton.

She was taken into custody and has been receiving treatment at the Alberta Hospital.

According to a psychiatric report, McNall told doctors, "I have to join her because she was everything to me, she was my whole life, I cannot bear this unwanted separation."

She will not be allowed to remain in Canada after serving her sentence.

Stevens worries what will become of her when she goes back.

“She is penniless. Homeless. Has health problems obviously,” she said. “And the doctor here has recommended a transfer from a hospital to a hospital. And we have not been able to get that worked out yet.”

McNall will be sentenced in January. Neither the defence nor the Crown is seeking any more time in custody.