GRANDE PRAIRIE, Alta. -- The mother of a Canadian who was arrested in northern Thailand on charges of spraying paint on an ancient wall says her daughter made a drunken mistake.

Tara Schneider, who lives in Grande Prairie, Alta., said she received a phone call from her daughter Brittney around 3:30 a.m. Thursday.

"She just said, 'Mom, I'm in trouble,"' she told The Canadian Press on Friday. "I said, 'What's wrong? Are you OK?'

"She said, 'Ya, I'm OK but I'm in prison.' I asked her what she did and she told me, and our phone call ended briefly after as they took her phone shortly after that."

Security camera footage shows Furlong Lee, 23, and Schneider, 22, spraying a message on the walls of the Tha Pae Gate in the northern province of Chiang Mai.

Col. Teerasak Sriprasert, chief of the Chiang Mai police, said the tourists are in custody and have been charged with vandalizing registered ancient artifacts, which carries a penalty of up to 10 years in prison and a million baht -- or $40,000 -- fine.

The chief said the pair admitted spraying the message out of drunken revelry. He said that Lee, who is from Liverpool, admitted that he wrote "Scouser Lee" on the wall, while Brittney told police that she wrote the letter "B" underneath it.

The 13th-century Tha Pae Gate is part of an ancient wall that forms a square around Chiang Mai's inner city.

Schneider said her daughter told her she was drunk and she was following along.

"After she wrote the letter B, she knew it was wrong right away," said her mom. "She knew and she discontinued the engagement."

She said she is overwhelmed by the charges against her daughter.

"You would have to know Brittney to know this is not her," said Schneider. "She is liked by many, she's got friends everywhere in the country. People are baffled.

"This is something you'd expect, no word of a lie, from my son. I'm sorry to say it, but not my daughter, not my Brittney.

"She never did a bad thing in her life."

An official with Global Affairs Canada said the department is aware of the charges against Schneider.

"Consular services are being provided to a Canadian citizen who has been arrested in Thailand," said a statement from spokesman Philip Hannan. "Canadian consular officials are in contact with local authorities to gather additional information."

Schneider's mom said they have been working with the consulate.

"We've currently sent the bail money. The bail was set at 149,000 Thai baht, which is $6,000 Canadian," she said. "That's been shipped off in the process and she will be released Monday."

Schneider said her daughter won't be able to leave the country until the trial, so she will fly to Thailand as soon as possible to be with her.

"I would like to be there for her during the time she waits for trial so she's not alone."