Majority of the time when people want the scoop on what is going on with any particular issue they pester the person/ situation because someone or something gave them the idea that you know what they want to know. Stop telling anybody that your aunt has issues, don't give it that energy.
Now it's not about declining them the information they want but to not know what they are talking about. If someone knows you have what they want, they'll never leave you alone but on the other hand if you slowly just don't know what's going on anymore and just play dumb. They ask; you don't know- tell them you are staying out of her personal issues now because it's not your business. But behind closed doors, you help the people you want and keep it to yourself.
When you don't have any information to give up, they will eventually leave you alone because you don't know anymore of what's going on so what can you tell them. It works well for noisy people.