No doubt she feels the loss of her husband very much, and I suspect she's still grieving over his death. Although her hope is misplaced, this may be the only way she thinks she can keep his memory alive.
If her husband somehow could return and spend even just one minute with her, I have no doubt that he would urge her to put her faith and hope in Christ alone. Her husband is now safely in heaven, and some day they will be together again.
But in the meantime, only Christ can save us, and He alone is the one to whom we should look for the help we need. The Bible says, "For there is one God and one mediator between God and men, the man Christ Jesus" (1 Timothy 2:5). Don't let anyone take Christ's rightful place in your life!
Pray for your friend, and urge her to turn to Jesus Christ for the peace and comfort she seeks. Few things in life are harder to bear than the death of a loved one -- but God knows what we're going through and can comfort our hearts by His Spirit. Jesus' promise is for her, and for all who are hurting: "Peace I leave with you; my peace I give you.... Do not let your hearts be troubled and do not be afraid" (John 14:27).