No astrologer in the world can ever predict longevity of a person. And if he does he is a fake astrologer. In your wife’s horoscope Saturn is highly benefic and is quite potent and will never do any harm. And her 8th house is the most powerful and therefore it can generally be said she will live long. Her Mercury is the weakest and that is what is causing problems for her in the abdominal region. Treat her with Ayurveda and she will be Ok. Read my blog navagrahastro.blogspot.in for more details.