Follow the instructions and start by paying mrv fee, fill out the ds160, schedule the interview & medical. Make sure she has all required documents ready. Your wasting time if you are doing nothing.
My fiancee didn't even have my divorce decree when she had her interview because the divorce decree is already in the petition itself. This is utterly strange. If you look at the list of required documents, the petitioner decree isn't even listed only the beneficiary's is required
Manila will not need an original of your divorce decree.
As an aside, you should be asking these Manila specific questions in the Philippines regional forum so you can avoid general replies from those unfamiliar with what Manila needs