In 1754 Jodocus Harmannus Berckhof married in Groningen with Marieke Freriks. In the certificate we can read that Jodocus originated from Lier Oostfriesland (Today: Leer, Ost-Friesland) and that Marieke came from Lier-Oord Oostfriesland. Unfortunately no ages are given. We only Marieke was assisted by her father Frerik Martens.

Who knows where they did live and who their family were?

Leerort is a place near the town of Leer, East Frisia, Germany.

Both have heritagebooks. (Ortsfamilienbücher, OSB /OFB)
Members of a mailing list Ostfriesland / East Frisia perhaps are able to help.

In the OSB Leer (luth) Nr. 10153 is listed

MARTENS, Frerik, /=OSB Leerort I 1317 ?/,
oo
HINRICHS, LISABETH
child:
Martha ~14./16.12.1733 Leer

So you will get your Mareike in the OSB Leerort