Are you spiritually drained by an adult stepdaughter that is a narcissist?

I have been plagued by a 26 yr old woman after marrying her father. She and her mother has used him to get his grandmother's 1/2 million dollars - neither one had lived with him for 20 years and they thought they were entitled to the inheritance. She left a message nearly a month ago saying she doesn't want to have anything to do with me...and he hasn't talked to her since. The problem here is that this young gal holds the "grandchild card." My husband wants to see his grandson and she knows it; now it's a battle to see if she can get him to go and see her 1500 miles away. I am saddened to be married to a man that has a daughter like this...and it has been hell ever since I married him 3 1/2 years ago. I am going to work on getting my spirit back ... this gal has broken me down these past few years and it's only now that I see what I need to do for myself. I contemplated divorce and that might still need to happen -- I have lost so much. Did I mention Dad is a narcissist, too?