When we were out one evening, our 14-year-old daughter had some friends round and someone brought a bottle of spirits. My daughter got so drunk that she passed out. Her friends called 999, and we arrived home to find paramedics in the hall. She says she's sorry and she won't do it again. But I don't know if I can trust her any more.
We all make mistakes. The trouble is, teenagers' mistakes are often spectacular.
This is why, when you look at your teenager with astonishment and say, "But why did you put the bread knife in the toaster/ film yourself eating cinnamon/ram the wrong key in the front door so that it broke in half and locked everyone out", he or she will probably look blank and say, "I don't know."
This willingness to try things out without necessarily knowing what's going to happen next sometimes produces wonderful results. "My 13-year-old put a small dead bird in the airing cupboard," says a friend. "When he looked an hour later, it was fluffy, cross and very much alive."
But most of the time, we don't get miracles. Most of the time, teenage experimentation leads to broken glass, burst pipes and late-night visits to A&E.
As all parents know (we have only to look back at our own misspent youth to remember), teenagers occasionally drink too much.
But, as we all also know, experimenting with alcohol can be extremely dangerous.
A drunk teenager risks being involved in serious accidents – anything from a head-on collision to falling from a window. And alcohol poisoning itself can be fatal.
But it's possible that this 14-year-old really didn't know what she was getting into. Teenagers aren't always that clear about the strengths of different kinds of alcohol, or how long it takes to have effect.
"You're feeling fine," says a 17-year-old I talked to, "so you drink more. And then suddenly you're drunk. And some people have no idea that you can't drink a whole glass of vodka in one go."
Sohila Sawhney from the charity Drinkaware says: "As a parent, the worst thing you can say about alcohol is nothing at all. It may be surprising to hear, but parents have the biggest influence on children's attitudes and behaviour towards drinking, so it's important to have informed, open and ongoing conversations from an early age.
"Medical guidance suggests an alcohol-free childhood is the healthiest and best option. It's important that children are aware of the many risks of drinking too much – you're more likely to be a victim or perpetrator of crime, or make risky decisions about sex."
Mark McDermott is professor of psychology at the University of East London and has studied teenage rebellion. When teenagers step over the line, he says, try to react calmly.
"Adolescence is a time of great transition. It's a busy developmental period. So it's important that parents don't add to the pressures by overreacting.
"The first thing to ask is, is this an ongoing pattern of behaviour, or just a one-off? If it's a pattern, it might be a good idea to talk to someone professionally, as the daughter could be acting out some kind of distress.
"It's definitely not a time to be heavy-handed or to impose sanctions. You risk alienating her and harming the relationship between you, and she's probably already feeling very ashamed."
If there are no lasting physical effects, this particular 14-year-old may be able to put it all down to experience. She has learnt a useful lesson, and will probably never drink like this again.
"My daughter once threw up for the whole weekend after going out on a Friday night and drinking vodka," says a friend. "She's 22 now and she still doesn't touch spirits."
If you want some ideas on how to discuss alcohol and its health effects, there are good safety tips for teenagers in the