Boyfriend's family is in the countryside and his parents have no social security.

First of all, there is no medical insurance and social security. After that, you have to pay for the doctor yourself. Health is another matter. Then you have to take the daily living expenses from you. If you are old, you should take care of their daily life. In case you lie in bed, someone must take care of you. You have to ask the old lady if she has bought medical insurance and social security, and what is the situation at home. In case her family is in poor condition and there is no social security insurance, she can take money to take care of it. Practically speaking, for the elderly, without medical insurance and social security, one more is better than one less, unless there is a recent demolition in your area, so many people are strength. There are many other aspects that you should consider carefully. One more thing, is the old woman strong? She likes to make her own decisions. No matter how she behaves, she will be very annoyed in the future.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.