HELP… purchasing a viola for my wife

My wife played viola as a young child until her father passed away at 17. It’s one of her life’s goals to play again. She has even mentioned trying find an orchestra or group to join. She’s turning 40 and I’m going to purchase a viola for her to start working toward that goal. I have 0 idea where to start, what to buy or really anything to do with the viola. Any advice is welcome…