A woman was almost three times over the alcohol limit when her car crashed into a mother of six on her way home from visiting her premature newborn twins in hospital, investigators said.

Alexia Cina's car "collided head on" with 37-year-old Katie Evans after crossing the center median of the Golden Valley Road in of Santa Clarita, according to sheriffs theCalifornian city.

Ms Evans was pronounced dead at the scene, the force said in a statement on Facebook.

They added Toxicology reports revealed the 21-year-old "had a blood alcohol content of .21", The legal limit is .08. Alcohol containers were also found in the vehicle, they said.

“Katie leaves behind her husband Jacob Evans, her children Spencer (12), Travis (11), Nathaniel (9), Gideon (2) and her premie twin girls Hannah and Sarah,” Ms Evans’ friend Natalie Mortensen wrote on afundraising page has been set up for the victim’s family.

“Katie couldn't go a day without visiting her brand-new twin girls in the hospital. She was a devoted mother, sister and wife and will be immensely missed."

She added that Evans' husband Jacob had been left to care for the six children by himself.

"There will be many childcare costs as well as unforeseen expenses.”

The fundraising page had raised more than $300,000 at the time of publication.

In a recent interview with The Signal newspaper, Mr Evans said he was overwhelmed by the outpouring of love in the wake of the tragedy.

“The public is offering so much already,” he said last week. “It is a huge wonderful blessing that we have such a wonderful community. We’re struggling just to sort through the offers (of help) that we’ve had.”