You must take daughter immediately to a psychologist or a psychiatrist because a suicide attempt is usually an urgent call for help. She is not able to deal with her problem effectively. Or she may be suffering from depression which may be because of psychosocial or biological causes. She is already indicating her problems. Try to be soft on her, give time to her even if you are busy because otherwise it may be too late. Listen to her, try to understand her feelings and thoughts without judging her,support her emotionally, guide and encourage her to talk about her problems. Help her to engage in good routine and hobbies. Hurry and get her medical help as advised.