I filed for legal separation and amend the petition to a divorce, do I have to serve her again?
No judgement yet. I just want to know if I'm legally required to serve my ex again since it is technically an amendment to the existing case and not a new case?
Generally, and in all typed of lawsuits, any documents filed with the court MUST be served upon the other parties to the litigation. Otherwise they do not receive notice of the issues before the court which is required in all states and jurisdictions. As to serving Amended Petitions, each state law varies on what is required. Has she answered the original petition? Has she listed an address for service? You may not have to "formally" serve her but rather just mail her a copy. But again, it depends on the stage of the litigation. I would check with the clerk of the court as to same if you are doing this pro se. There may be a pro se clinic or he or she can point you in the direction of the statute that applies (they are Procedural statutes). The clerk can not offer legal advice.