Legal Question in Criminal Law in California

They never told her? She should file a complaint with the State Bar of California.

The prosecutor could possibly have other evidence other than your testimony (what you told the cops the night it happened, the 911 tape, the X-rays of your broken bones) and this could have persuaded the public defender to recommend a deal. If in fact there is no case without your live testimony, she could well be successful in withdrawing her plea, and she might have a lawsuit against the public defender's office (watch out for short legal time limits for filing claims against the county). No way she will be successful without hiring a lawyer. If she beats the case, she will then want to consider filing a motion for a Declaration of Factual Innocence.

Now about you.

None of the above excuses your sorry self for staying with her, going back to her, etc. Nothing good is going to come from continuing a relationship with a physically abusive individual. She's not marriage or motherhood material -- do you want to father a child abuse victim, or a foster child that you won't be allowed to see? Next time around you could be the criminal defendant, child support payor, or homicide victim. Please find a support network and develop a backbone.