A friend of my aunts who is in her mid 60's has had extremely severe tremors of her upper extremities.?

You should also do some research on Familial Tremors. Normally, alcohol relieves them somewhat and that may explain why she is drinking. A big factor is caffeine. Drop it completely...from all sources (yes, even chocolate). The best clue would be for someone to ask her if one of her parents was afflicted the same way. It's most noted when lifting/holding something. Also affects writing. Another word for it is Essential Tremors. There are some health gurus who claim to be able to relieve the symptoms through diet. But there are some challenges. Probably the best food for it is sourkraut...ugh.