In these sentences instead of わたし could it be replaced with they/she/he pronouns?

For example would karera wa o sushi tabetai ga desu/カレラわ おすしたべたいがです (sorry if I have spelt something wrong) make sense? Or is tai/ Tell only for personal use to express desire to do something?

btw this subreddit is a LIFESAVER I’m actually so grateful 🙏🙏