Sometimes the best thing a doctor can do for us is to tell us honestly when we need surgery even if he knows it will be painful and upsetting to us. But beyond the pain and the upset will be healing and that's what we need.
The same principle may be true for your friend. Sometimes the best thing we can do for someone is to confront them with the truth of what they are doing (or failing to do). It may be painful and upsetting to them but in the long run it's the only path to a better life for them. Unless this happens, your friend will almost certainly keep repeating the same mistakes over and over again. The Bible says, "The tongue of the wise brings healing" (Proverbs 12:18).
Ask God to give you the wisdom to know what to say to your friend that will truly help her. Don't be judgmental or harsh, but let her know that you genuinely care about her. It's natural to blame others for our problems; Adam blamed Eve for causing him to sin, although he alone was responsible (see Genesis 3:12). But simply blaming others never solves anything.
Most of all, encourage your friend to give her life to Jesus Christ. He loves her and knows her needs, and if she will commit her life to Him and follow Him, many of her problems will vanish.