Your mother bought insurance, which has nothing to do with your grandmother. As long as the salesman asks the right question, it doesn't matter if your mother tells the truth.
About your uncle and aunt? Please refer to the first question.
As long as you fulfill the principle of telling the truth and the insurance company underwrites it, there is no problem. Besides, I'll give you a suggestion. When buying insurance, you'd better ask the salesman to fill out the insurance application form and record your conversation. In case of insurance accident, this is the best evidence.
Finally, I will tell you some legal knowledge. In addition to the principle of telling the truth, the insured should also ask for information, that is, you can say whatever the salesman asks, and it goes without saying anything. Another key point is that if the salesman knows, it means that the insurance company knows. Your uncle and aunt are not healthy. In order to get insurance smoothly, salespeople often help them hide their illness. If you have a recording, as long as you tell them truthfully, you will take the initiative to sue.
That's a little too much. I hope it helps you.