only you know the parents so go by what you know. My niece lost a baby a couple of years ago and even right after it happened she would get really upset when others tried to act like the baby didn't exist. She was born too early and only survied a couple of days. For my niece if I would omit the baby from anything she'd be very upset. I know that everyone is different so this could up set her or act as a comfort to her.