Well we had a long chat last night. Ds said he hadn't spoken about it because he just didn't want to talk about it, but wouldn't say why. I think perhaps because he knew if he did he would get very upset and cry so he was just keeping it all in. It's a hard conversation to start, and I understand his reluctance.
I did say I thought it was important to talk about things that upset us a lot, that it didn't have to be to me, but that keeping it all in can make things worse sometimes and be a heavy burden to carry.
He was very tearful and worried about gf clearly. I asked if he thought she would have gone through with taking the pills if her friend hadn't intervened, and he said he didn't know. I explained that sometimes people told others they were suicidal as a cry for help, and that I thought this might be the case here, as she gave warnings to a few people, and hadn't actually taken the pills. I said this to try and reassure him a bit, as my understanding of what's gone on is that gf is having a very tough time and needed somehow to let the outside world know how very bad things were for her at home.
It turns out her grandma has just died, and her parents' behaviour is causing her a lot of unhappiness. They live under the same roof but are separated and fight a lot, so I think gf has possibly felt invisible and alone at home.
It's a very sad situation, but I gather the police were involved and she is having counselling, so I hope that will enable her to feel less unhappy, and will make her parents aware of how miserable their behaviour is making her.
We had a more general conversation about suicide as well, and I impressed on ds the need to talk to someone if he ever felt very low, because even if he felt like things could never get better for some reason, talking to someone was really important because when we feel low we're not always able to see things clearly, take a step back, etc.
My neighbour's son committed suicide a few years ago, I watched him grow up, and it has been so so sad to see the consequences for his family. His father is a broken man, consumed by grief, still going to the place it happened every day to light a candle. My uncle committed suicide too, so it's a very real worry, as I am acutely aware of how someone can take their own life without others being aware of their mental suffering, and not recover from the awfulness of it.
cory so sorry to hear your dd has been very unhappy, I hope she will get through the sadness and see a brighter future ahead. Must be terribly terribly hard for you as a parent 
quietly I don't feel I have the right to interfere atm, ds is very mature and level headed, his cousin always phones him first when she's in a pickle, and he manages to give good advice without getting too involved if that makes sense. He would lose all respect for me if I tried to stop him seeing her, plus I think she could do with some support in the way of just having a normal time when she's not at home. Now I know what's been happening at least I can monitor the situation.
It's just really hard when things like this happen as it highlights to me the fact that no matter how much you want to, you can't protect your children from encountering difficult situations or save them from suffering.