Catharina Treu (May 21, 1743-October 11, 1811) was a German still life painter and a member of the Treu family of painters from Bamberg.
Biography on Wikipedia: https://en.wikipedia.org/wiki/Catharina_Treu

Still Life with Fruit by Catharina Treu
1768 / Oil on canvas / 24″x20-1/2″ / Found on Bavarian State Painting Collections online

Catharina Treu on Artnet: http://www.artnet.com/artists/catharina-treu/past-auction-results

Further reading:

Netherlands Institute for Art History
Portrait of Catharina Treu with pallet and fruit basket translated from German
A Bamberg Family of Painters translated from German