If my daughter's mother has just become engaged to a registered sex offender, can I get an order of protection to keep this predator away from my child?

I would try to find out information on what the terms of his conditions are.  Some offenders are ordered to stay away from children so this could be a violation. If he's permitted to be near children and hasn't done anything improper towards your child, it will be an uphill pattle to get one.