Well, this is really bizarre to know that the lady is occupying your property and you could do nothing.
Surely there is way to deal with the situation irrespective of her political patronage.
First you have to clarify how she occupies your property.
if it is father;s property , he can file a suit for eviction.
if she indulges in criminal activities and police is in hands in glove with her then you can seek intervention of high court against such police inaction.
Case of criminal trespass lies against her and your citizenship issue is of no consideration here.
Take help of a seasoned lawyer locally or from this site.