Help with pronouns

So, I'm making a custom Magic set and there's a question that has been on my mind ever since.
Do we call creatures by their pronouns, other than "it"? (e.g.: "it gains lifelink", etc) ?
I have this legendary creature who's a female character. Do I put "her" in her ruling text?
Or do we simply put the creature's name instead? I'm really confused...