Only speaking to what I know:

Cuba - It will be a pain for you to handle the paperwork. As an American, you have to pick only one of right reasons to go to Cuba and going on vacation isn’t one of them. You also can’t go to fancy hotel since they are owned by the Cuban state and the USA embargo means you can’t trade with the government directly. You also need to keep all receipts for a few years.

Puerto Rico - Pretty stable as a place to visit, especially in touristy areas.

Turkey - Istanbul is a great place to visit and it is easy to get around. I also hear the beaches are great. Only possible issue is that Turkey is rather hilly and I don’t know if your mom can handle the hills.

Scotland - Nice place to visit, but you aren’t going to be going to visit any beaches. Also, you’ll likely be drinking in front of your mother.

Portugal - Nice place to visit. Very hilly. The area is also adjusting to its tourist demand.