The homestead should unlock gradually based on the Star Stones you find during the game. Your Rift Travel icon should flash every time that happens as a reminder to visit the homestead.
Spoiler (mark to uncover): Beware that Blood Stones are corrupted Star Stones, and that you have to use them to "free" the Star Stone inside to count for the homestead. You expend their one-time healing power doing that, though.
