ok, first of all, I want to say sorry to hear about your g/f's mom, and I think it's cool that you would consider giving half your liver to someone who pretty much hated you.

secondly, I want to say that a person does not belong to their parents after 18, but also if you are married... if you think about a wedding ceremony, doesn't that dad walk down the aisle with his daughter to 'give' her to her new husband? so she kinda belongs to her husband, well ok, they belong to each other...

and lastly, I don't think they should starve her to death, I don't really believe that they should euthanise her at all, but if they do, they should at least do it a little more humanely.