I'm sorry to hear that your hamster isn't doing well. You have apparently done a great job of taking care of her because she is the equivalent of a human in their 80's.
As hamsters get older, they become more prone to some diseases that can't be treated. The symptoms you're seeing are common with these illnesses, so that is definitely one possibility for what is wrong. Some of their organs can become embedded with minerals. They can develop cardiomyopathy and heart failure. Cancer and strokes become quite common. You can read more about hamster old age here:http://www.hilltopanimalhospital.com/hamsters.htm
I'm afraid that your hamster most likely has one of these illnesses of old age. If after reading about the diseases of old age, you decide that's what's wrong, all you can do is keep her comfortable. You're already doing a good job of that. Of course, there's a possibility that this may be something treatable. To be sure, you'd need to make an appointment to see a vet. After an exam, the vet can determine if your hamster can be treated. If so, the proper treatment can begin. The following links will take you to directories of vets who treat small rodents. At the first site, you'll come to a log-in page. Sign in as 'Guest' and use 'Guest' as your password XXXXX well.
If your hamster is a Syrian (teddy bear, golden, fancy) and your house got cold last night, she may ahve gone into hibernation. Hamsters will go into hibernation when they feel chilled. Even a few degrees drop in temperature overnight can cause it. It's not good for them to hibernate and wake up repeatedly, as it's hard on their bodies, so you do want to try to prevent it. Your hamster should be in a room where the temperature evenly stays around 70 degrees. If you don't have a room like that, you can buy one of the heating pads that are made to go underneath reptile cages. Most pet stores carry them. It would be put under the hamster's cage to maintain even warmth. The best way to warm a hibernating hamster is in your hands. As they come out of it, hamsters can shake violently. If your hamster is hibernating, it will take about 30 minutes to an hour of warming in your hands to bring her out of it.
If you have further questions, just let me know by clicking on REPLY. I do hope it will turn out that your hamster is only hibernating.