I didn't find a baptism record for Thecla (also spelled Teila)
in the St. Vitus, Altenoythe parish records. These records
do contain some Gröneweg families who might be related.
One strong possibility for Thecla's parents appears in
a 27 Feb 1701 baptism record of Maria, daughter of Joannes
Groneweg and Maria Meijer. The godparents there are Egbertus Ditraub?
and Tecla Gröneweg.
Another possible relative is Joannes Gröneweg. Joannes and his
wife Thecla were parents of a son Joannes Antonius, baptized
21 Nov 1725, with godparents Henricus Huisman and Margaretha
Maria Tameling. Still another is a 1737 baptism for Meinardus Antonius
Gröneweg, son of Egbertus Gröneweg and Thecla Tameling.
Joannes Willer was the godfather for that Meinardus (Gesina
Maria Tameling was the godmother). Egbertus Groneweb is
the godfather for Thecla's daughter Margareta in 1724, so
I would guess Egbertus is probably Thecla's brother.