Puzzle - Prussian descendants

NO CHANGE SINCE 1Q

My grandfather Paul Wilhelm Schlegel immigrated to New York City from Kolmar, Posen, Prussia in 1891, followed in 1894 by sister Emma Louise.  

Of their family remaining in Prussia, we do not know what became of
     - older sister, Anna Louise SCHLEGEL
     - Emma Louise's twin brother, Emil Heinrich SCHLEGEL
     - younger step-brother, Otto Julius SCHULZ
as highlighted in family group sheet, below:

    VOGELSANG, Emma Pauline   1851 Kolmar - 1941 Rügenwalde ?

    SCHLEGEL, Georg Burchard     1842 Kolmar - bef 1887, likely Kolmar       

          Anna Louise                             1871 Kolmar - ?        

          Paul Wilhelm                             1874 Kolmar - 1929 NYC   my grandfather 

          Emil Heinrich   (twin)              1876 Kolmar - ?           

          Emma Louise     (twin)              1876 Kolmar - 1947 NYC   immigrated also

    SCHULZ, Ewald                         unknown - aft 1890, likely Kolmar

          Otto Julius                                1888 Kolmar - ?

          Emma Matilde                           1890 Kolmar - 1958 Lichtenfels  

               *marries                          

          PELCHEN, Reinhold

               Christa Hildegard Wilhelmine      1914 Kolmar?   - ?

                   *marries

               WINKEL, Friedrich Hermann Christian                            

Of their mother Emma Pauline and step-sister Emma Matilde, we know they relocated at least twice, likely due to changing borders after WW1 and WW2:

   1910 - 1914 ?          Kolmar, Posen, Prussia        now Chodiez, Poland

        We have photo postcards of both in front of "their shop" [1]

        Emma Matilde married in 1913 and daughter born in 1914 -- in Kolmar? [2]

   1929 - 1938             Rugenwalde, Pommern        now Darlowo, Poland

        Emma Matilde's daughter Christa confirmed in 1929, and married in 1936 [3]

        Emma Pauline living with Emma Matilde and husband in 1938 [4]

   1953 - 1958             Lichtenfels, Bavaria   

        One of Emma Louise's children visits from New York in 1953 [5]     

        Emma Matilde dies in 1958 -- in Lichtenfelds? [6]

We do not know if Emma Matilde's daughter Christa PELCHEN WINKEL had any children; online searches have not turned up anyone with surname Winkel in that area today.

Records found:
   1842-1876 births - Schlegels / Vogelsangs, church records
   1888,1890 births - Schulz, Otto Julius + Emma Matilde, civil records

Records not found:

   1956 death, Emma Matilde Schulz Pelchen - Lichtenfels?

   1941 death, Emma Pauline Vogelsang Schlegel Schulz - Rugenwalde ?

   189x death, Ewald Schulz

   188x death, Georg Burchard Schlegel

   18xx marriages - Schlegel / Horn, Vogelsang / Zieske

   18xx births - Schlegel, Horn, Vogelsang, Zieske

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SOURCES

1.   1891 emigration papers, in the possession of Nancy Schlegel

2.   1891 Manifest, Wilh. Schlegel

3.   1894 Manifest, Emma Schlegel

4.   Church books for Kolmar, Posen, Prussia

5.   Civil records for Kolmar, Posen, Prussia