The fact she is a peace is the most beautiful and solice thing you could wish for! I am soooo sorry this hard time is apon you and your loved one. I know it will be hard for you and the ones she will leave . Know that she will be in a state of love, beauty and white light on her passage to a better place~
If there is anything you need, a friend to grieve with, scream at or just talk to ...I am here for you!!!
I can't think of anything to add to all the wonderful things that have all ready been said. You and her (and your families) are in my prayers and on my mind. May you find peace in your heart knowing you did just what she wanted.
I'm sorry. I can't even begin to imagine what you're going though. At least you both have some time, and it's not so sudden that you can't say goodbye. That's probably no consolation at all. But I wish you and your family and your housemate the very best and I'll be praying for you.