We are truly sorry to hear about the loss of your wife's friend and the struggle she is now facing with depression. It's important to remember that God is always with us, even in our darkest times. As it says in Psalm 34:18, "Yahweh is near to those who have a broken heart, and saves those who have a crushed spirit."
Firstly, we want to address that we only have access to God and salvation in the name of Jesus Christ. It is important to come before God praying in Jesus' name and having a relationship with Him. Believing in the death and resurrection of Jesus Christ is the only way to salvation as it says in Acts 4:10-12 "be it known to you all, and to all the people of Israel, that in the name of Jesus Christ of Nazareth, whom you crucified, whom God raised from the dead, ... There is salvation in none other, for neither is there any other name under heaven, that is given among men, by which we must be saved!"
In times of grief, it's common to feel depressed and withdrawn, but it's crucial to encourage your wife to turn to God for comfort and strength. As it says in 2 Corinthians 1:3-4, "Blessed be the God and Father of our Lord Jesus Christ, the Father of mercies and God of all comfort; who comforts us in all our affliction, that we may be able to comfort those who are in any affliction, through the comfort with which we ourselves are comforted by God."
We encourage you to continue reminding your wife that you and your daughter are there for her. It's wonderful that she finds solace in talking to your daughter daily. Encourage her to open up about her feelings to you and perhaps to a trusted Christian counselor or pastor. It's also important to pray together as a family, seeking God's healing and comfort. As a loving Christian husband, pray for Jesus to give your wife the strength and comfort that she needs.
Let us pray together:
Dear Heavenly Father,
We come before You in the name of Jesus, lifting up this family who is going through a difficult time. We pray for your wife, Lord, that You would comfort her in her grief and heal her from her depression. Help her to cast all her anxieties on You, because You care for her. We pray for restoration and joy to fill her heart once again. We also pray for their marriage and daughter, that You would bind them together in love and strength during this time. Guide them in Your will and give them the wisdom to navigate this season. We ask in Jesus' name. Amen.
Lastly, we want to encourage you to be patient and loving towards your wife. Grief has its own timeline, and it's important to allow her to process her emotions while gently guiding her towards healing and restoration in Christ. Remind her that she is not alone, for God is always with her, and so are you and your daughter. Remind her in the truth of Romans 8:38-39 "For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor things present, nor things to come, nor powers, nor height, nor depth, nor any other created thing, will be able to separate us from the love of God, which is in Christ Jesus our Lord."
Prayer Focus: God, Thank You. Thank You for loving me. God, I ask You in Jesus’ name bless me with everything that I stand in need of and everything You want me to have. Bless me to know You in truth, fall in love with You with all my heart, mind, soul, body, and strength and never fall out of love with You. Bless me to have an ever growing closer stronger, more intimate relationship with You. Bless me with the love, desire, strength, and the spirit of obedience to always delight myself in You, seek first Your kingdom, and Your righteousness. Help and strengthen me God to always respect and obey You. Bless me to trust You with all my heart, acknowledge You in all my ways, and lean not to my own understanding. 
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