The Mother and father had 3 children - 1 son and 2 daughters. All born
in Europe. The lived in PA.

Both daughters had a SS#, and I have requested the original apps for
one. If this yields no info, I will request the app for the other.

One daughter's marriage lic yielded no info. I have not requested the
other, as it likely would yield same results.
Son never married/

Ellis island records do not help.

I suspect I have addressed all the obvious approaches.

Family entry to the US was approx 1905 - 1910 for all arrivals.

I am looking for any ideas on other possible approaches / documents
that I might try in the US.

Howie Axelrod