Whoever the woman is or was, she or her heirs own the copyright, whether or not it was ever published before.

So publishing it under your own (or anyone else's) name, instead of her's, would be a breach of copyright.

But I don't see why you shouldn't publish it under her own name, as you seem to know what that is.

Knowing her name ought to make it easier to trace her - I didn't realise from your original posting that you knew her name.