You are doing all of the right things. While I don't advocate begging and pleading, I do not think you are in the scenario where you go dark on her either. The little thoughtful things you have been doing has been fine. Had you asked, I would have suggested something less associated with romance than the chocolates and flowers....something that shows you know her. Since the kids will be away from her for awhile, perhaps you could help them pick out something for her from them.
As for these "divorce" talks: I do not think it's wrong when it's brought up that you express that divorce isn't what you want, but you understand if it's something she feels she needs to do. She might be probing to see if it's something you want. You kind of came full circle from begging and pleading and perhaps she thinks you've accepted the divorce.
You cannot be lonely if you like the person you're alone with. Dr. Wayne Dyer