Little cons are survivors they will probably evade the jack until large enough to fight back. You may end up losing a few.
Maybe try a few out in the tank with her overnight and see how it goes. With enough hiding spots for the little cons there shouldn't be an issue with that much tank space and such small fish.
You may lose a few Cons but I think most should be okay for a while. Cons breed young and small, so releasing 15 in an aquarium and keeping them in there for several months will lead to several pairs and more fry. Multiple breeding pairs of Cons can be a lot of trouble, especially for a young and reclusive female JD.