Ongoing fight with sister-in-law... call and check on her after her miscarriage?

To start things off, I am not officially her sister-in-law yet but knowing her so long, we have had many big sis/little sis talks and i consider her one of my own siblings, despite the fact she is my fiance's stepsister. But during our time together she confided alot in me... later including that she was 16 and dating a 21-year-old she was running away to on the weekends. She told everyone BUT ME she was already pregnant when she went to go live with him, but the truth is she planned to get pregnant after she moved in with him and successfully did so. I consider her one of my own siblings and did all i could to reach out to her, but when a fight occured between her father and my fiance's mother, she cut off all contact on her father's orders. I respected the distance her father asked for as i would not want someone undermining my parental authority if it were me. We both got pregnant around the same time but i lost my baby at 2 1/2 months; she just miscarried too about 3 or 4 days ago. I want to call her up and try to console her because, like i said, i don't see her any differently than my other sisters and i know what she must be feeling right now as it just recently happened to me too. But the fight between my fiance's mother and her father has driven us so far apart. I am afraid that 1) she will resent me due to the drama between her father and stepmother, and 2) speaking to her will only further the feud going on between her parents... My little sister needs my help, what do i do?!