Assuming you are referring to how to refer to your child when they are not present, the best way is probably to ask them what pronouns they would like you to use. If they haven't come out as non-binary yet, you could try using gender neutral pronouns such as they/them or ze/hir. If you're unsure about which pronoun to use, it's always best to err on the side of caution and use the pronoun that your child is most comfortable with.