My Neighbor's Keeper (2007)

Kate Powell was a happy housewife with her husband Tim and accepted working with small children in hospital who lack motherly love. When her best friend Ann Harding gets murdered at Halloween, she becomes her little kids Logan and Ellie's surrogate mother, while widower Mike Harding, who wasn't home again, blames himself for having put his business before his marriage, and gets rid of some of his materialistic show pieces. Then the theory rises that Kate may have wanted kids too much...