Shinn, Sharon. Elemental blessings novel #5

"Valentina Serlast has reluctantly traveled to the royal city to witness her brother Darien be crowned the king of Welce. A hunti woman with an affinity for the forest, Val is much more comfortable living in isolation on her country estates, almost forgotten by everyone. When Darien convinces her to extend her stay, she is drawn into an unfamiliar whirl of activity, meeting with ambassadors from other countries, becoming friends with the unpredictable Princess Corene, and trying to learn the secrets of a glamorous foreign visitor named Melissande. But nothing makes Val more breathless than the reappearance of Sebastian Ardelay, a red-headed rogue who has been her best friend since childhood. She quickly learns that Sebastian has been risking his life in a dangerous venture that could get him banned from the kingdom-or even lead Welce to the brink of war."--Amazon website