Who can help identify the author of Painting?

[Valerit]

Purchased by the city of Tartu. From a good family .
J. Clover influence , and perhaps a copy.
German?
In Estonia, "everyone" German painting.

Clever young little studied in A. Hagen in Tartu (up to 17 years of age ). I saw the picture with the signature clover and Hagen.
Hagen August Mathias died in 1878 in Tartu. Maybe someone of his disciples ?
 The picture looks like the beginning of the 20th century.
The frame and subframe are original, clearly not in Estonia. Canvas with a factory primer.

This work is long and that nobody could say something.