In Faerie there are two big political, social and magical divisions. Winter and Summer. Within those there are other smaller ones, such as the faction that has formed around the heir to the Throne of Summer. Said heir's title is the Lady of Spring and so her faction is known for that season. Dana and her friend Feidelma belonged to that group. One of the things their Lady was interested in was to end the Tithe to Hell. This ideas was controversial in Both bigger Courts for various reasons, mostly having to do with how many lives both fae and human have already been lost or damaged by the Tithe.
Those who are spend much time with the Lady of Spring and her supporters may also be referred to as the Young Court. Whereas those who support Titania are known as the Old Court. This is perhaps a bit indicative of the general age of those in said Courts as the older a faerie is the more likely they are to give their support to the Queen over giving it to her daughter. Whereas most of the younger fae, (those less than five or six centuries old) tend to approve of the ideas and policies of the heir.