Your daughter's suicidal gesture or serious suicide attempt was her desperate scream for help. Now is the time for your daughter to get the professional help that she needs to treat her depression. It's also the time for you to come to a more intimate understanding of the inner life of your daughter's mind and heart and how you can best assist her in her climb up from depression. I believe that you have been the most loving parents that you know how to be. Do not fault yourselves for her torment. But with good therapy you may learn how to develop an even better relationship with your daughter. When we know better, we do better -- and that goes for forging relationships with our children, too.
Your shock will soon give way to using therapy as a way to reconnect to your daughter in the ways that she needs you most. Do not be discouraged that things don't change for the better in short order. She needs you to abide with her as she summons up the courage to battle her demons and to learn how to feel better about herself and her life. This takes time and the support of her family and friends. Therapy should not be seen as the means to "cure your sick daughter." A talented therapist will see her in the context of being a member of your family, a teenager who has a social world, an individual who has formed her own beliefs about herself and her life, etc. You may be asked to have a very active role in the therapeutic process or not, depending upon the approach of the therapist(s). Make sure that she and her therapist are a "good fit" and that she feels that she can form a trusting bond with that person. I am sure that you will open your minds and hearts in your attempt to help your beloved daughter back into the light. She will cling to your unconditional love, courage, empathy, and patience like a rock.