WW1 German Dec. 1915 dated postcard

A very nice WW1 German postcard that shows a women with a child surrounded with the national German colours and national eagle.
Further more the text (roughly translated) “With best Christmas greetings”

On the back the card is written.
Hard to read and translate, because it is written in old style German.
Card is probably posted in France or Belgium.
It has a stamp with (hard to read) “21 I infantry reserve battalion 6^th comp.”.
Card is dated with the date stamp 13 or 15 december 1915.