Damia's Children by Anne McCaffrey

Here McCaffrey introduces another generation in her saga of a family of powerful psionic Talents ( The Rowan and Damia ) raised to serve the Nine Star League. The eight children of Damia and Afra Raven-Lyon approach the threshold of maturity on Iota Aurogae, where they have been raised with young Mrdinis, the only other intelligent life that humankind has encountered--save for the pernicious Hive Culture, which has sought to destroy all other species in its drive to expand through the universe. The eldest teenager, Laria, is sent to the homeworld of the Mrdinis to improve relations between the two species. Thian, the oldest boy, encounters residual human prejudice and almost loses his life when he serves as liaison with a mixed human-Mrdini fleet.