Therefore the question is: HOW MUCH LONGER DOES SHE HAVE????

And Pablo is correct, it will depend on a lot of variables about which we know very little. This is for certain, there will be parts that are going to wear at that mileage and beyond, so I would expect your costs to begin to rise, but, of course,nothing is for certan. Usually, people who don't have a great deal of disposable income will wait until they are faced with making that decision, rather than trying to second-guess it. In other words, when your costs paid and costs facing you are greater than you want to spend, then it's time to look for a new car. This might also partially dictate what car you will get because of availability. On the other hand, if you simply want to trade to a newer/different car, then your question is irrelevant.
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John Shatzer, '92 965 @100K; one of a few still in captivity.