Ask HN: My wife might lose the ability to speak in 3 weeks – how to prepare? 6 years ago
get a great microphone and have her read her favorite books. Go for books with lots of dialog and emotional content.
Later, you can extract all the phonemes you want from it and you will retain the emotional expressiveness of her voice.
She should probably sing some songs -- lullabies, rock, etc. Go for emotional diversity.