Here's a picture of the signature.

Here is a link that might be useful:

The Dona Rosa pottery that is most valuable is the ware with the decorative cutouts. Those with appplied or other sorts of decoration bring lots less.
Off the top of my head I would say about $20....depending, of course on size and condition.
The name Dona Rosa now refers to lots of ware made my a pottery on Oaxaca. I believe at one time there was really a Dona Rosa that developed the polished black ware with the cut out decoration...but any more I think it just refers to the pottery made on one factory in Oaxaca.
Linda C

By factory I mean a pottery where workers are making pottery to sell there....factory was not the best word.
Yes it was most likely hand made. But it is not the most desireable example of Oazaca pottery. The pieces with the precise and decorative cut outs bring the most $4..
As I said, in the neighborhood of $20.
Linda C

Here is a link that might be useful: Dona Rosa

This does not look like Dona Rosa's signature

What is the real signature from Dona Rosa herself?

Did she make also traditional masks?

And as far as I can find, she didn't make masks.