Hi, This Is. Quarantine Question. My Mother In Law Lives

Question : Hi, this is. quarantine question. My mother in law lives with my sister in law. Her name is XXXXXXX XXXXXXX has dementia and XXXXXXX my sister in law has been caring for her for a month now without help. My husband is concerned for his sister is asking that we go there (my mother in law has her own apartment that they can also go to) to take care of her this Saturday. XXXXXXX my husband, and I have been quarantining for a month now. Our friend shops for us and we rarely go out - really just to get the groceries from our friend and to bring down the garbage. Maybe twice a week for 30 minutes. We are working hard to social diatance.
We put this off a bit, but i thjnk we will have to do this this Saturday. i really do not think it is a good idea. My mother in law is 90, My husband is 66 and I am 65. My sister in law lives 16!blocks from whaere she will bring my mother in law - her apt. To be clear they keep two apartments. XXXXXXX lives with Thersa all the time. They drive by personal car to the other location and we all ride elevators to leave our apartments. XXXXXXX and I will walk 8 blocks to get to her apartment. We have N95 masks left over from painting.
Please tell me what you think. I want to be fair to my sister in law and my husband, but frankly i dont agree with this.