Not sure a chicken egg will stand up to a goose sitting on them our being moved around next to goose eggs. 11 eggs sounds like she maybe getting close so just try and wait it out, some aren't happy till they have upwards to 20 so be sure to mark all the eggs so you can remove the oldest when she does begin to sit. Once she is in full broody mode you can begin to whittle down her clutch to a more reasonable amount by taking out the oldest dirtiest eggs.That is unless you want 15 to 20 goslings.Why don't you put some of the chicken eggs in the goose nest. She may then be satisfied she has a large enough brood. She'll hatch both kinds if she starts setting.