Sweetie, even if you could have convinced her out of it that night, she WOULD have done it eventually anyway.. I know that hurts, but it's true. This is small comfort, but at least she wasn't alone, and had someone who cared about her with her that night. And I'm certain that Jesus himself came to escort her home.
I've tried suicide a few times. The first was around 12 or 13, with a pair of my mom's sewing scissors. Luckily, I'm a wimp and I hate pain, so I chickened out of stabbing myself.. lol.. Suicide is the cowardly way out of this life. So many people choose suicide because it's quick and works most of the time. They don't realize that suicide only creates MORE pain for those left behind, who have to deal with the sorrow and guilt and anger. I want you to please read both my depression and suicide threads below in my siggy. And check out my faith book in the Miscellaneous forum.
Maybe it will inspire you to do one for your friend.