The mother left when he was a baby. She never looked back. There were a few times i heard she had paid 30 - 60 dollars for child support but that is it. My son has no idea who she is, what she looks like or that he has half-siblings
Since that is the case, I'm sure you would have no problem terminating her rights. Your struggle will be with your ex. I would consult with a children's attorney so you are well advised of your rights.