I am very sorry to read this, but it seems that things do not look optimistic. You are the only one who can make the decision, and it sounds as if she has reached a point where you need to watch carefully for any indication that there may be discomfort. Cats are way more stoic than dogs when it comes to this, or maybe it is just easier to tell with a dog....it could be the survival instinct in the ancestors of cats. CHF has a tipping point where there is suddenly a crisis so you want to monitor carefully. Your concern for your friend at this time undoubtedly mirrors the love and care that you gave her during her lifetime.