You need to do something. You can't even see what is happening.
Every time she asks a question that regards you backing off, you feel the need to remind d her that she left you. If you want this woman to want you, stop reminding her of the things that annoy her.
She is feeling your distance. Let her. Let her experience that without your play by play.
You complain that she needs to grow up, but you continue to coddle her in a way. A grown woman who decides to separate from a marriage does not need to be told why you are distancing yourself. It should be obvious.
You have been separated for a year, correct? And your behavior continues the same, it's what she expects. So stop giving her what she expects. That is what husbands and wives do, the luxury of marriage. Stop telling her why you are doing what you are doing.
Focus on yourself. And September is coming. You already know what that means.
