Legal Question in Civil Rights Law in New York

First, whatever your father "plans on" doing must obviously be appropriately planned while he still alive, by either executing a will or establishing a trust. If his will were to say that you and your sister would be the devisees of the house, presumably as a tenancy in common, then her rights would not trump your rights. Each of you would have equal rights. Which is a problem, because the relationship between you and your sister is clearly not good. There will need to be cooperation between the two of you. You don't say what other assets, if any, you expect to be part of your father's estate, but if it were possible for you and your sister to divide up the assets in a manner that would obviate the two of you sharing a single asset, that would obviously avoid a good deal of feuding.

Good luck to you.