first of all
Welcome to the Banater schwaben Forum!
If your Grandmother doesn't appear in the Kleck documents, probably she was registered in the documents from Zrenjanin, a Town very close to Kleck (3 miles). Try to research also in this direction, the former german name of Zdrenjanin is Gross Betschkerek, the former hungarian name - Nagybecskerek.
P.S. Do you know the
Donauschwaben Villages Helping Hands
? They have a lot of links to documents, family books and so on... Try to click over "Research" on the top of their homepage!