Carol,
To put things in perspective, the family were very poor and she would not have any sort of fashion budget - clothes were bought only as necessary, not on a whim. That was why I said she may have dipped into her grandmother's trunk for the photo.
The main characters are the soldier husband Pawel Balcarek I don't know his date of birth but he was killed fighting in France on 11th November 1915. His wife Franciszka (possible maiden name Gawlik) again no date of birth but this photo shows her with 2 very young children. The younger was Wilhelm Andrzej Jerzy Balcarek and Polish Air Force records show him to have been born on 4th February 1915. So that and his father's death date were only about 9 months apart and he looks to be 6 or 7 months old in this photo. I have no information on the other child.
From this I conclude that (regardless of fashion) the photo WAS taken in 1915 OR somebody has totally misidentified the photo and the baby is actually Pawel and the photo is from a generation earlier.
No living person can actually answer that question as the youngest person [nominally] in the photo would be 106 if alive to day and about 25 years older if it was misidentified by a generation. The only hope I have is to try to identify the uniform. Is it German, Prussian or Austro-Hungarian and that would be more likely to accurately date it.
I have no idea about fashion and I don't dispute the comments that have been made but I have to wonder whether a truly poor woman would wear something enormously out of fashion in order to be photographed with her husband and children knowing that he could be killed at any time. Being photographed at all would be more than she could afford under normal circumstances.
But my main criteria is to get it right - even if I find that I am totally wrong in my thinking. Accuracy is more important than my personal vanity'
Neville
