I'm hoping someone who lives in the South of France and reads this boards will offer to do some leg work for you.
I have very little access to records for people who could possibly still be alive (I have pretty good luck finding their ancestors) but I'll do my best to see if I can find out anything for you.
Do you know anything else about her? Any little bits of information will be helpful such as:
Do you have the names of any of her relatives?
Do you know where she lived before she went to Nice?
Do you know her occupation?
Please let me know as much about her as you can. You can post it here or send in to me privately.