We all know someone who needs to change, but doesn't; a person who has a persistent sinful habit they admit to participating in, but refuse to stop.
As a biblical counselor I face situations every day with people who readily admit their sin problem, are experiencing consequences from that sinful problem, yet refuse to repent and change.
As people involved in soul-care, it is very easy to become frustrated and angry with such people because we know how to help them! We know the end of the road they are on if they continue. We give them the answers, they agree with us, and continue on in sin anyway.
What to do?
One thing you can do is to remind yourself that you are not in charge of changing or "fixing" anyone. The responsibility of any people helper is to deliver the message, pray, and continue to exhort the counselee or friend.
The message to deliver is that of reconciliation.
Now all these things are from God, who reconciled us to Himself through Christ and gave us the ministry of reconciliation, 2 Corinthians 5:18 (NASB)
Our Lord is in the business of reconciling sinners to Himself. It is good to remember that God calls sinners while they are still sinners (Romans 5:8)! Having this attitude is Christ-like and will show through your words and your body language as you meet with your counselee or your friend.
Continue to give the gospel and remind your unrepentant friend of God's love for wandering sheep. Teach her from the Scriptures about consequences for sin being a love-reponse from God and about the reconciliation that is offered through the cross. If she professes to be a Christian, it doesn't mean she doesn't need the gospel- we all need it every day!
Guard your own heart.
It is so easy to become angry and frustrated with unrepentant people. The tendency is to just give up on them and tell them you cannot help them. This would be a tragedy. While you can't change anyone, you can continue to plant and water and hope that seeds of repentance take root in her hard heart.