We are truly sorry to hear about the situation you're facing. It's important to remember that our ultimate help and comfort come from God, and He wants us to cast all our anxieties on Him because He cares for us.
Firstly, it's crucial to understand that our bodies are temples of the Holy Spirit, and we should honor God with our bodies. Your loved one needs to take care of herself physically as part of honoring God.
When people won't take care of themselves there is little we can do. God has given each of us free will and we must choose to do the things that are best for us. Think of the story of the prodigal son. He had to learn the hard way. The father did not lecture or pressure the son in any way. He allowed him to learn from his mistakes.
1 Corinthians 6:19-20 WEB "Or don’t you know that your body is a temple of the Holy Spirit who is in you, whom you have from God? You are not your own, for you were bought with a price. Therefore glorify God in your body and in your spirit, which are God’s."
It's also important to remember that guilt is not from God. Conviction is from God, but guilt and condemnation are not.
Romans 8:1 WEB "There is therefore now no condemnation to those who are in Christ Jesus, who don’t walk according to the flesh, but according to the Spirit."
You mentioned that you can't have her stay with you because she is difficult. It's important to have boundaries and remember that it's not your responsibility to fix or save anyone especially if is not your spouse. You can pray, encourage, and support, but ultimately, each person is responsible for their own actions and choices.
Galatians 6:2 WEB "Bear one another’s burdens, and so fulfill the law of Christ."
Galatians 6:5 WEB "For each man will bear his own burden."
Let's pray together.
"Father, we come before You, lifting up this situation. We pray for healing and comfort. We ask that You would give her the strength and willingness to take care of herself physically as a temple of the Holy Spirit. Help her to make wise choices and to surrender her life to You. Lord, we also pray for the one submitting this request. We ask that You would remove any feelings of guilt and replace them with peace and trust in You. We pray that they would learn to set healthy boundaries and to trust in Your love and care for them and for those they love. Lord, we also pray that the name of Jesus Christ be lifted up in this home and lives. Help them to know that there is only one way to heaven. In Jesus name."
Lastly, we want to encourage you to examine your own life. Make sure you have surrendered to Jesus Christ as your Lord and Savior.
Romans 10:9 "that if you will confess with your mouth that Jesus is Lord, and believe in your heart that God raised him from the dead, you will be saved."