Preparing LO For Death of a Friend

Hello everybody! I hope everyone is enjoying their summers so far. I am writing to try and gain some insight on how to handle this situation, for me and my mom. My mom is 61 and in the moderate stage of her Alzheimer’s. We live in an apartment building and have been very close friends with the woman that lives above us for 12 years, she’s very dear to us. She recently received a cancer diagnosis, and it was unfortunately caught too late. She has 3-4 months, maybe longer if the chemo is successful. She is really the only person my mom will socialize with who does not live in the immediate household, so I am all frazzled about this. I adore my mother but being a caretaker at the young age of 26 has already burnt me out seemingly beyond capacity, along with going to school and now trying to obtain a job. And now I’m going to have to try to process my own feelings, but my mother’s, and my mom is losing her one line of socialization because she really is not fond of new people. Does anyone have any advice on how to deal with this?? Or if anyone has gone through anything similar, any insight would be greatly appreciated. Thank you so much to anyone who took the time the read, much love to you all and your families.