You can't make a hen go broody. If she is only ten weeks old, then there is no way that she will be ready to go broody. Generally, hens that are prone to broodiness go broody in the spring or summer. Fall/winter is the 'off' season for hens. It's the time of year when their bodies are recuperating from a long season of turning out eggs.
Brood the chicks indoors with a heat source to keep them warm. Once they are mostly feathered in, you can start putting them in a pen adjacent to your Barred Rock during the day so they can see each other and socialize, and still keep the little ones safe. Once they are big enough to handle pecking order scuffles, and fast enough to get away, you can start to allow you older girl to interact with the little ones. Once they can spend most of their days without altercations, you can let the little ones be with her full time.