She had been working on Christmas Eve, had come in and sunk two bottles of wine while wrapping presents until five in the morning.
The next thing she knew, she was stumbling downstairs with a hangover, to be greeted by the dismayed faces of her two young daughters – then aged 16 and five – upset that she had missed most of the day. It was two in the afternoon and they had already unwrapped their presents.
She had been drinking, though her husband did not drink. For years she had been in the habit of opening a bottle of wine every night, as she had a job in an ice cream van and didn't have to be up in the mornings. "It wasn't just because I'd been up wrapping. It was down to the drinking," she explains.
"I was already drinking. Christmas time just gave me an excuse to drink more. My daughter Zara was just in P2 and until then she had been going to the nursery in the afternoon. Even then I still missed it," Catherine recalls. She cannot remember what her girls' reaction was that Christmas. "My daughters had tried to wake me. I don't know, embarrassed, upset? I can't really recall. They never said too much."
She partly blames a troubled childhood – in children's homes and foster care – for her drinking.
"I was very anxious as a child and in adulthood. Drinking would take that away," she says. But it was a guilty secret. "Nobody knew I was drinking behind closed doors. I was holding down a job. People think it's just down and outs that are alcoholics. There's a real stigma."
Catherine has been chosen to back a new campaign to get adults, and particularly parents, to re-examine their attitudes to drinking at Christmas.
It is being run by the Glasgow-based Violence Reduction Unit (VRU), which is holding an alcohol conference in Edinburgh today to encourage parents and carers to think about how their actions can affect their children's attitudes to alcohol in the future.
While the link between violence and alcohol might be obvious, changing the attitudes of parents might not be the most obvious role for the VRU.
For Chief Inspector Graham Goulden, however, it is part of a wider need to change the culture around alcohol in Scotland.
"We often point the finger at young people for their underage drinking and so on. But it takes place against a background of alcohol-adoring adults," he says.
"Every generation takes its cue from its parents and we celebrate alcohol and laugh at the negative consequences."
In fact, if parents do not have firm opinions and attitudes on alcohol, it is hardly surprising if their children soak up bad examples, he says.
"Parents who come in after a hard day at the office and say they need a glass of wine or a beer are linking stress with alcohol and sending a message."
The campaign features an animation to accompany a reworking of the Twelve Days of Christmas, sung by the Lothian and Borders Police Choir, and with new lyrics. These list drinks instead of gifts ("Five ports with cheese, four pints of beer, three swift halves, two cheeky shorts ...") as a way of suggesting that the Christmas drinking can add up and drawing attention to the way many of us mix drinks and overindulge at this time of year in a way we normally would not.
The obvious charge that this casts the VRU as killjoys is, perhaps, part of the problem.
"We don't need an excuse to drink in this country; deaths, weddings, births, divorce, it's the elephant in the room," Goulden says. "We are not saying you can't have a drink at Christmas, but it is almost as if people have a privilege to go out and drink an excess amount of alcohol just because it's the season. We are not saying you can't have a drink in front of children, either. But be aware you are being watched – you want to make sure the consequences will be positive."
The VRU conference includes presentations from journalist Nicola Barry, who has written about how she was affected by her mother's alcohol dependency, and from psychologist Dr Aric Sigman, whose hardline attitude is outlined in his book Alcohol Nation, about protecting children from our drinking culture.
Dr Sigman says: "We used to think teaching responsible drinking was the way forward. We were wrong.
"We are now seeing young people with liver damage in their teenage years and some people dying from liver disease in their 20s. Evidence now suggests that the earlier people are exposed to alcohol, the more likely they are to become addicted.
"If children are exposed to alcohol when their brains are still developing, there is evidence it affects the frontal lobe, leading to more risk-taking and poor impulse control, not just now, but also a year on from when they drink."
The brain goes on developing into your early 20s, he adds, and parents who believe that children would drink anyway, regardless of what they see at home, are mistaken. "The idea of forbidden fruit is a myth. Kids will experiment, but if you can show you disapprove of drinking and don't provide the alcohol, the result will be fewer children with alcoholism now and decades from now."
This is one occasion where adults are entitled to offer children a double standard, he adds. "This is a case where that is reasonable. You can say, 'do as I say, not as I do – because the effects on me are entirely different'."
The VRU campaign also includes tips for parents on sensible attitudes and responsible drinking; including the obvious ones about nominating a designated driver and buying less booze, but also suggesting ideas like letting young people see when you are hungover and not disguising the effects of alcohol. "Don't let them think hangovers go hand in hand with a good night," it suggests.
Several months after her Christmas afternoon wake-up call, Catherine finally quit booze. It took her that length of time, she says, because she initially tried to do it without help, but insomnia saw her repeatedly relapse, knowing wine would help her sleep. Following two weeks in a residential alcohol treatment centre in Ayrshire, Abbeycare, she gave up completely. Seven years later, she is the centre's deputy manager.
She is divorced now; her marriage was "one of the things I had to change," she says.
And she does think people should examine the effect that their drinking has on their children.
"I would come home at night and open a bottle. My daughter noticed, and knew it would mean trouble. She would say, 'Dad will be angry, Mum's got a bottle of wine'."
"Deep down I was conscious of that, but when you are in it, it's hard.
"I've seen lots of people who have been through what I've been through and bitterly regret the effect it's had on their kids."