In the baptism records of St. James Lutheran ("Straw") Church in Greenwich, Warren Co., NJ there is a baptism for Balthazar and Anna Barbara. It is in 1770 and says this:
Balthaser Buckel [Biickel] and wife Anna Barbara--(child) b. July 8, bapt. Aug. 12--Sponsors Balthaser Bickel and wife Anna Barbara.
The record above only says "child." I don't know if it was Mary or Nicholas, but I would guess Nicholas. I think he was younger than his sister, Mary. I would think that Mary was born before 1770.