If my grandfathers will stated that in his death the farm goes to my dad and in the event of his death to me does my sister have any rights to the farm?

bro , legally if the papers are to u or ur dad , then LEGALLY she dont hav any rights over the farm but you can give her a letter of authority from which she will give sum rights or u can divide the land and legally give it to her !! then she has legal rights over it !!! :)