The role of a parent is to have a happy child. Not a cis, straight child.
If parents make the CHOICE to have a child, they should be prepared to love that child however they come. Not force or traumatise them into being who you want them to be. It doesn't work and that trauma will remanifest itself sooner or later.
It's not the kids who are not confused. It's their parent's who are enforcing their bias on who THEY want their child to be. Bias rooted in homophobia and transphobia.
If your cis-gender son knows they are a boy, then so does your transgender son. If your heterosexual daughter shows an interest in boys, then why validate that, but discourage your other daughter who's interested in girls?