Well, what type of nest site are you planning on giving her? [below ground or above ground]
When I kept germanica, I made a large cardboard shelter in the enclosure, but I made it different than for Polistes. I enclosed all sides and most of the bottom. I put the one side piece on in a way that made a nice gap as an entrance. You can glue an embryo Polistes nest in the shelter and see if she uses it. The shelter should be more enclosed than the typical thing we use for Polistes