@Chotiari Your fighting an uphill battle.
Oldest refused to talk to me for 2 years over politics. she was in the liberal college factory at the time. Now shes moved to California to pursuit a career. During her last visit home she looked at me and said, "academia is a scam" I just politely agreed. Common sense will prevail, once person is removed from group thought. Just be there for her and avoid arguments. Just accept that she has her own view and have faith hers will change with time.