Oh Im so sorry to hear about this!

Has she ever had health problems before or was this just a sudden unexplained thing? How terrible for her, you and your family. My prayers are with you!
They make low sodium tomato sauce now! You could make a spaghetti sauce using that. I'd ask the doctor to make sure though just in case. I don't know how much sodium is in pasta itself but I do know that most red sauces are loaded with it. So the low sodium one might be a good way to let her enjoy her pasta still! My grandfather is on a low sodium diet and has been for most of his life. I know he eats normal foods but they are fresh foods and baked/broiled, not fried. He also stays away from red meat. He buys salt free potato chips and peanuts. Its not a horrible lifestyle change. Just takes some adjusting. Good Luck!!!