Blue Dahlia by Nora Roberts

A Harper has always lived at Harper House, the centuries-old mansion just outside of Memphis. And for as long as anyone alive remembers, the ghostly Harper Bride has walked the halls, singing lullabies at night
Trying to escape the ghosts of the past, young widow Stella Rothchild, along with her two energetic little boys, has moved back to her roots in southern Tennessee - and into her new life at Harper House and In the Garden nursery. She isnt intimidated by the house - nor its mistress, local legend Roz Harper. Despite a reputation for being difficult, Roz has been nothing but kind to Stella, offering her a comfortable new place to live and a challenging new job as manager of the flourishing nursery. As Stella settles comfortably into her new life, she finds a nurturing friendship with Roz and with expectant mother Hayley. And she discovers a fierce attraction with ruggedly handsome landscaper Logan Kitridge.
But someone isnt happy about the budding romancethe Harper Bride. As the women dig into the history of Harper House, they discover that grief and rage have kept the Brides spirit alive long past her death. And now, she will do anything to destroy the passion that Logan and Stella share...