poor kitty

My cat is dying. I don't know when, but it's got to be soon. She doesn't seem to be in pain, but she obviously has very low energy. She can't keep her food down and is now eating and drinking very little. Okay, I knew this was coming, she is 19.5 human years old. In cat years she's a 94 year old lady and still very spry until a few weeks ago. I hate to "put her to sleep." Even though it is merciful in many situations it still feels like taking a life. I don't think I can do it this time, not unless she seems to be in intolerable pain. AND tomorrow is the teenager's 14th B day! It would so suck to have the cat die on his birthday :o(. Friends are coming over after school, and you know, cat death is a real downer. What ever happened to the simple days of my childhood when cats just ran away, never to be seen again?