Help with an Antonio Rotta painting?

I have an Antonio Rotta painting that I THINK is authentic. There are noticeable brushmarks on the canvas and the frame, etc. appear old. My grandmother got it at least 30 yrs ago. I have researched and couldn't find the painting anywhere. It pictures an elderly woman sitting at a table, peeling an egg for a child, I think it's a boy. It's fairly large, about 28x26? What do Antonio Rotto paintings go for? My most important question is whether anyone knows of any existing paintings by him that fit the description above. Thanks for all info!!