My 82 year old mother recently moved in with my sister after the passing of our father. Any advice on what is best to do with profits from selling her home?

Kim, the profits from the sale of Mom's house will have zero impact on social security or Medicare. Put the profits into a bank account that is only used for Mom's care.

Keep records of every dime spent from that account, receipts, etc. I use to make a copy of the receipt with the original check placed on the receipt in a spot not to cover any important information, then I placed the copy into a 3-ring binder. This will be very important when the time comes, if at all, that Mom needs to sign up for Medicaid [which is different from Medicare].

I agree with Barb above, time to make an appointment to talk with an "Elder Law Attorney".

We haven't yet, but sounds like it would be beneficial.

Have you consulted with a certified eldercare attorney? That is probably the best investment you can make right now.