My father (1919-1984) married a woman (born in 1922) in 1943 and had a daughter on 6/18/44 whom her name is unknown, prior to getting divorced and marrying my grandmother.
They were married for only a few years.
The marriage took place in NYC, same about the birthplace.
Me and my siblings (all from the 2nd marriage) are desperately looking for our half-sister.

The information we have is:

• Marriage certificate containing my father and his prior spouse details and birth date
• Birth record of my sister containing the date (no names)

I've tried searching their names on FamilySearch and Ancestry etc. and found no results.

Is this the right board to post names?

P.S. Both my father's and his bride's surnames are very distinct names, I'm sure it refines the search options, does it?