Dawid RISS and family

Many years ago a request came for information about David RISS from Lubaczow. David RISS had signed the birth certificate of  the father of the person who wrote me, and he did not know what the relationship was.

Now, using the civilian Death Register and  the graves identified, this is what happened to Dawid Riss' family.

Dawid RISS, born ca 1867, was the son of Hersz and Rachla Laja RISS.
Dawid married Reizla RISS nee RISS , born ca 1872, the daughter of Abraham and Sara RISS.
They had at least these two daughters:
Gitla Mirla RISS  born ca 1896.
Chana RISS, born ca 1904.

These dates tell the story:
On Nov 18th 1919 Dawid RISS died and was buried on Row 3, Grave 19.
On Dec 24th 1919 the daughter Chana RISS died, 15 years old. No gravestone located.
On May 13th 1920 Reizla RISS died and was buried in Row 23, Grave 30.
On May 17th 1920 the daughter gita Mirla RISS died, 24 years old, and was buried in Row 23, Grave 29, next to her mother.

What the relationship was, is still not clear.